Projection Screen is done!

Someone stole my microphone pod from the spray booth. After forty minutes on the rotary polisher, it looked altogether much better, and I'm rather angry that someone stole it.

(If you, the thief, are reading this, please be noted that I'm going to pull your pancreas out through your nose with a butterknife.)


On the plus side, I've built a rather nifty 76" projection screen out of some blackout cloth and "stretcher bars" - interlocking wood bars that artists use to strech canvas. I paid under $30 for the whole thing, including fabric.

There are a few advantages to this method: The screen is stretched tight and smooth, and is very light. All that's required for assembly is a stapler and scissors; no power tools are needed.

Color correcting sheltie.

This is my dog. She's a cute little sheltie, a little over a year old, and I love her a lot.

(awwwwww.)


I need to learn how to do color-correction, though, and this seems like a good starting point.

Any tips, anyone?

Microphone

This is my microphone. There are many like it. But this one is mine.


It's going to have a Transsound TSB-165 capsule and a Schoeps circuit.

It'll look better tomorrow.

Did I mention I made the whole thing by hand? That copper ring is a copper pipe cut-off I filed until I was rounded; the brass rod is a bit of brass rod; the mesh was stamped into place with a dapping block, and the little copper rings were made out of a coiled piece of copper wire.

Yay for hard work.

Yay! I'm updating again!

Well, now that summer's almost here, I'm going to be updating again. However, it won't ALL be speakers - some of the stuff here will be covering recording equipment, and some of it will simply be twisted products of my own imagination.

Anyway, as I do not yet drive, I'm stuck imagining all the awesome cars I'd like to own. And I figure I ought to post one every Sunday, if only because I think of the silly things so often.

Car #1:
Homemade Lotus 7, A.K.A "Locost", with turbocharged Hayabusa engine.

The Lotus 7 is, by nature, a pretty simple concept: Make the car very light and streamlined, and it will go fast. Due to its simplicity, it is also the subject for a remarkably popular book: "How to build a sports car for under 250 pounds (british currency)." These low-cost sportscars, or "locost cars", are a great way to drive a glorious old roadster without the insane pricetag and annoyingly maintenance-intensive nature associated with

Trevor Davis' Locost Car of the Year, 2005

The majority of Locost cars use old 4-cylinder engines, usually those from cheap economy cars. While the cars they come from are often quite slow, the vastly reduced weight and excellent agility of the Lotus design make it a drivable sports car. As an added bonus, the engines are usually quite cheap - hence the 250 GBP theoretical total pricetag. And, in the case of many Honda engines, there are a wide variety of cheap aftermarket parts, which can turn a $2,000 roadster into a $3,000 four-wheeled missle.

However, massive horsepower is going to require a massive engine. While the end result is certianly an improvement over the engine from your Geo, the bigger engine does go against the philosophy of Lotus design: "Add Lightness." The Lotus was designed to be as light as possible.

But what if one could have the best of both worlds?

Enter the Hayabusa.

To put it simply, the Hayabusa is very likely the fastest bike on the planet. With the stock 170hp inline four-cylinder engine, it can reach speeds of well over 180mph. Of course, so can competing bikes from Yamaha and others...but that's only half the story.

Photo courtesy of super7cars.com

Apparently, the astounding 170hp from the Hayabusa's little 1.3 liter 4-cylinder engine is only scratching the surface. You see, the 170 horsepower from the tiny little 4-banger is the spec for normally-aspirated engine, fresh out of the box - no tuning. In its eight years of production, the Hayabusa has generated a large number of aftermarket parts - and these are what truly make this engine impressive.

While 170 horsepower seems insane from an engine the size of a breadbox , that's nothing compared to a fully 'rodded Hayabusa. With the addition of a turbocharger or supercharger - for which there are multiple options - and a bit of tuning, 300 to 400 horsepower is not uncommon. There are reports of maxed-out Hayabusas, equipped with nitrous injection, capable of over seven hundred break horsepower!

Caterham Super 7 Hayabusa

In fact, Caterham has built exactly this: A modified version of the Lotus Seven, called the Caterham Super 7 Hayabusa. Availible from the factory with up to 350 horsepower from a modified Hayabusa engine, it's one of the fastest cars made today, capable of leaving Porsches and Ferraris in its wake. It boasts a 0-60 time of under 3.5 seconds, and that's for the baseline 185hp version.

Of course, anything this awesome is not going to be cheap. But then again, there's a thriving community of people building knock-offs of exactly this car. Considering that a Hayabusa enigne can be had in very good condition for less than $3,000, why not just build one yourself?

Well, I'd like to. Eventually.

Maybe.

Next week: Mopar hoonage!

Musical Genuis

Here's a really nifty video of Herbie Hancock jamming on his Fairlight CMI, one of the first polyphonic sampling synthesizers. With all the ridiculous stuff today, it's nice to see a very advanced piece of machinery playing good, old-fashioned music.

http://www.youtube.com/watch?v=n6QsusDS_8A&eurl=http%3A%2F%2Fmusicthing%2Eblogspot%2Ecom%2F

The Insignia B-2111 and you.

I'm looking at getting a few pairs (!) of these suckers used, and for good reason: They're terrific speakers at a terrific price. Despite being sold under Best Buy's house brand - the poorest stock of a truly awful electronic store - they're remarkably good. In fact, they're so good that Best Buy incrased the price from $45 a pair to $70 a pair - but they're likely worth it anyway.


Though the speakers appear to be yet more of the single-driver trash passed off as HT gear, they're actually 2-ways - that bump in the middle of the driver is actually a tweeter, mounted within the center of the woofer. While unorthodox, this "coaxial" design is nothing new - Tannoy has been using this configuration in terrific studio monitors for decades.

Aside from the unusual configuration of the drivers, the coaxial unit is itself something of an oddball. Unlike many cheap imitations therof, the woofer is real carbon fiber, and the tweeter is a real silk dome - no mylar junk or textured paper. The box has a rounded back - almost unheard of for units actually made out of MDF instead of cheap plastic - and is of remarkable quality. Even the finish is pretty good.

If one digs beneath the surface, the source of the speakers' unusual quality is evident: They're actually just a stripped-down version of Radiient's Europa surround-sound satellites.

The Real Radiients

Radiient came out of nowhere in something of a Cinderella story, except that Cinderella was not staffed with some of the best audio engineers of the buisness. Notables include the guy who invented the HDMI 1.3 standard, and from what I've heard, many people jumped ship from Energy - a now-defunct brand known in its own day for producing high-quality, reasonably priced speakers.

Though originally regarded as an excellent value at the $200 original pricetag, the Europas are availible today for just $100 a pair - and with free shipping, no less! Of course, many ask: Why send away for a pair of speakers when I can get some essentially the same at my local Best Buy for $30 less?

That $30 pays for a plethora of improvements - some visible, some not. In order to deal with irregularities on the high-end response of the coaxial driver, the Europa features a supertweeter - the funny bump on the top - to handle the ultra-high frequencies. In addition, partially as a result of the supertweeter, the crossover is of higher quality and a better design.

Unless you're ordering the B-2111s used or getting them on sale, I'd strongly reccomend the Europas. I've only heard the B2111s myself, but for the extra $30, you get quite a bit for your money!

Why conventions rule.

Princess Leia plays DDR. Q.E.D.

The CONstitution.

I am now officially a sci-fi convention (or "CON") vendor. As a vendor, I now have several rules that I request those persuing my wares to consider.

1. Do not take up all of the poor booth-person's time. You may be very interesting, and they may not be allowed to move, but the poor guy behind the table really needs to be able to sell stuff to other people, which this makes difficult. Furthermore, while we are required to be nice to you, we often would rather be running and screaming.

2. My stuff is not a place to put your food, drinks, etc. etc. etc. I do not care at all if you "won't knock it over" or if I'm "being silly;" I do not want your Frappuchino introduced to the insides of my $300 projector that I need to sell very badly.

3. When I get out of the dealers' room, I bloody well want to do something fun. While I am always happy to talk money, just because I'm here to buisness does not mean I am absolutely exhausted and need a break. In fact, it means I need to have a break a lot more, because, unlike you, I am here for profit.

4. If you do not think my prices are reasonable, I will, in fact, negotiate. Probbably a bad standpoint, but hey, I'm flexible. This is not a complaint - just a statement.

5. If you are a webcomic artist in the vendor's room, you had better be ready to deal with fanboys. By "Fanboys," I mean "Me." I could be described as a webcomic whore. On the plus side, I am at least a helpful fanboy, and try to buy something if I can.

6. I have a tradition of fixing something every year. Last year, I fixed someone's Xbox. This year, I fixed someone's Wacom tablet stylus. Hopefully, I will continue this in the future.

7. I am a lazy dolt. I apologize for not having buisness cards. Please do not hate me!


After three hours of sleep and severe fuzzy-mouth from a lack of teethbrushage, and general grogginess (need...diet...Jolt...Cola....), I am nonetheless pleased. The fact that I now have $380 in my pocket (up from $85 when I walked through the door) might have something to do with this.

A tube amp kit worth the money.

Not all tube amps are created equal - and, for the price, many compare poorly to well-built solid-state equipment.. However, if you're willing to forego some of the nicities, there are a few kits that, thanks to a combination of low cost and high performance, can compare very well to similarly priced solid state amplifiers with the "tube sound" people love. While I would not reccomend these to most over a solid-state amplifier, if you really want a tube amp, these are hard to beat.


One of the best of these is S-5 Electronics' K12G, availible for only $156 for a full stereo kit, or $100 for a mono kit, should you desire to build one. It's a classic push-pull amplifier with a solid, low-distortion design. Though the output power is a paltry 8 watts per channel, this all-inclusive design requires no external preamp, and makes a fine match for a pair of high-efficiency speakers and an iPod.


Another useful kit, should you require a tube preamp for the vintage amplifier of your choice, is the 12AX7 preamp from Silicon Chip magazine. While I can't find where to buy the kit for the life of me, the design is both solid - featuring a low distortion 12AX7 tube with frequency response compensation - and cheap, thanks to a simple yet high-efficiency switched-mode power supply running off a 17v wall-wart.



If you want to create the preamp yourself (it's simple, and you can just use a transformer instead of the switched-mode supply if you want), take a look at Mark Houston's excellent build guide. It's a great site, and also contains information on the K12 mentioned above.

And I'm back!

I'm currently at OddCon in Madison, WI. Anyone who wants to meet me, feel free to show up. (I'm the sorry SOB with the computer parts in the dealer's room.)

Anywho, this means two things:

1. I will be bored stiff;
2. I will be writing a lot.

And now, because I can't !@#$@!$ sleep, I'm doing a quickie article on a very decent deal : Madisound's Vifa 2-way car audio kit.

Link


This is a pretty dang ordinary system. It features two tweeters - Vifa's D26NC05 - and two Vifa autosound woofers. Included to make them work is a good, old-fashioned passive crossover.

The fact of the matter is, these are good, solid drivers, and a well-designed crossover. While not flashy or impressive, the performance should be very good indeed; Vifa OEMs parts for many middle-of-the-line audio brands including Paradigm, and the D26 is known for above-average performance in dozens of designs.

In addition, you can mount the tweeters on your dashboard with the included mounts. While not exacly pretty, it does make mounting easy for those of us who are less hardware-minded.

Just be sure to add a subwoofer - those 5.5" Vifas are not going to cut it!

In an attempt to make my blog less dull, I'm now featuring Cool Stuff Tuesdays™. As everyone knows, Mondays are not as awful as Tuesdays - on Mondays, the shock and horror of the work week has yet to set in. While certianly exciting, most of the stuff featured will most assuredly be of the type which we mortals simply cannot afford.

This week: Speakers.

1. B&W Nautilus

Photo courtsey of Bowers & Wilkins

Made by famous British speaker manufacturer Bowers & Wilkins, the Nautilus line is a great speaker continuing a great line of other great speakers. Originally starting as a supply house for DIY enthusiasts, their reputation for quality quickly forwarded them to making high-end studio monitors for the BBC.

Today, B&W makes studio monitors for several major record labels, in addition to a wide array of fantastic home-audio products. They have a reputation for top quality and advanced design, often featuring their signature yellow kevlar-coned woofers. They were amongst the first to utilize computers in design in the early 70s, and have not ceased, with designs nearly unrivalled in their precision. Quality has improved with technology, and today's B&W's are the best yet.

Instead of ordinary boxes and miniature chambers behind the tweeters, B&W instead used an elaborate series of several transmission lines, one for each individual driver. While hideously complex and difficult to build, the seperate enclosures allow for carefully optimized loading of each individual driver.

Bowers and Wilkins builds the speakers used to master the music, and these are an improvement upon them. They have a decades-long reputation for quality, and are well known for terrific and reliable sound. And, not surprisingly, they don't come cheap - they cost $60,000 a pair, not including the multiple high-end amplifiers necessarily to properly drive them.

2. Magneplanar 20.1s

Photo courtsey of magnepan.com. Lady in spiffy suit not included.

Most speakers have bits of metal or textile moved by a magnet and coil. They trade off size for frequency response and resonances, and at less than ideal frequencies will "store energy" - keep producing a sound even after the signal is removed.

Of course, others came up with different solutions - ribbons and electrostatic panels. The former is usable only at high frequencies by nature, and while electrostatic panels are very nice, the spectacularly thin mylar used for the diaphragm is rather fragile - and the high voltages both attract dust and hurt a LOT.

Of course, Magnepan simply combined them to solve the problem. The Magneplanar transducer, Magnepan's signature product, consists of thin strips of metal over a stretched diapgragm similar to electrostatic transducers. However, unlike electrostatics, the magneplanar uses the strips of metal as a voice coil, moving the diaphragm between magnets on opposite sides.

The added mass does, however, slightly damp treble response - and, as a result, Magnepan added a large, high-quality ribbon tweeter next to it. While standard as far as most ribbon tweeters go, that's like saying it's average for a ferrari - ribbon tweeters are expensive to build, and their popularity is not a coincidence.

Magnepan has been making their signature flat speakers for years, and the 20.1 - as the lady's attire in the photo will suggest - are not the newest of designs. However, that's not a coincidence - despite problems with off-axis response and poor low bass, they've sold extremely well, and many feel that the $12,000 a pair pricetag is worth it.

3. Wilson Audio Alexandria X-II

Photo courtsey of wilsonaudio.com


$135,000. The price of a house. Or a pair of speakers.

Wilson Audio has a long reputation for impressive - if hideously expensive - loudspeakers. Originally custom-designed as monitors for the Wilson audio labels, the speakers soon after became sold commercially to great acclaim. Some people find their less expensive speakers, the Watt Puppies, not worthy of their $22,000 pricetag - but few cannot be awestruck by the Alexandrias.

To put it simply, the Alexandrias are the furthest extension of ordinary loudspeaker design. They consist of ordinary woofers, mids, and tweeters, all in ordinary - if seperate boxes. However, each and every part of the speaker has been extended to the extreme.

Those glossy boxes are'nt just for show - the speakers are made out of a phenolic resin through and through, far stiffer and acoustically dead than any wood product. Each cabinet is carefully braced, and resonance is reduced to a minimum.

The drivers themselves, however, are now slouches - the tweeters are the best ring-radiators that scan-speak has to offer, and the mids and woofers are no slouches either. Distortion is as low as modern technology allows for, and though I have no info on the crossover itself, it's undoubtedly just as intricate.

Of course, excellent design is not cheap - and it's arguable that there are few that would argue that any loudspeakers, regardless of quality, are truly worth $135,000. However, regardless of price, these are some of the best speakers ever made.

My System - Pt. 1

While posting about the intricacies of stereo components is all very fun, I feel that I should take this opprotunity to do something that all audiophiles are prone to: a little bragging.

My system, as it's shaping up right now, will be:

Source IBM X40 or other PC
DAC: Edirol USB ADC/DAC
Alternate CD player: Denon DCD-695
Amplifier: MyRef.A amplifier w/ passive preamp
Speakers: Modula MTs (not done yet)

Total cost:

Speakers - est. $200
Amplifier - est. $100
DAC - $8 at a garage sale
PC - I already own it.
CD player: $7 at thrift store.

Total: About $325.

This should beat the pants off of $1,000 factory-made systems, if half of what I hear about the Modula MTs is true.

What amplifier is best for you? (pt.1)

Tube amplifiers are traditional, and many audiophiles feel that tube monoblocks are the best amplifiers around. However, the price for good quality tube gear is high - with the exception of some cheap Chinese-made amplifiers, a full tube setup can cost hundreds and hundreds of dollars. Is the extra cost worth it?

In a word - no.

Tube amplifiers are inherently superior to transistor amplifiers by nature, but with the exception of some really high-end tube amplifiers, the number of compromises that must be made generally results in poorer quality sound for the dollar. Furthermore, many faults of transistor amplifiers can be overcome by simple good design.

For starters, tube amplifiers run at high voltages - often 300v or more - and are very inefficient. This means that power supplies are expensive, and the output power is generally very low. The price of a tube is also far greater than that of a transistor, while due to the complexity, the tolerances are also far more loose.

Furthermore, because they're power hogs and expensive, less of them are used. A tube amplifier often has only one or two stages for the pre-amp and power amplifier, making compensating for the non-linearity of tubes - which is often very high - a difficult task.

However, the #1 problem with tube amplifiers is in the output transformer - the device that allows the high-voltage low-current output of a tube amplifier to drive an average pair of high-current low-voltage speakers. These devices work like any other voltage-to-current transformer, but they must work equally well at both very low and very high frequencies - a difficult task indeed.

While it is possible to build a transformer that will work at frequencies from 20hz to 20khz without distortion, most tube amplifiers make compromises to cut costs - such high-end transformers can be hundreds of dollars apiece. Many transformers do not function properly at lower frequencies, or have internal inductances that eliminate higher frequencies.


As a result, most tube amplifiers - I.E., those that cost less than $500 after including the preamp and phono stage - simply can't compare to a well-made solid state amplifier for the same price. Distortion is higher, power output is lower, and several other annoying characteristics, like warm-up time, make a good solid state amp a better choice.

On the other hand, tube amplifiers do have their own merits. When a tube amplifier attempts to go above its maximum voltage output and "clips off" the top of the sine wave such as may happen during a loud cymbal crash, the distortion is far lower and less unpleasant than that of a solid-state amplifier. In addition, tube amplifiers - especially "single-ended", or class-A, tube amplifiers - have far less of the crossover distortion found in most solid-state amplifiers.

While there are plenty of stellar tube amps out there, most people simply cannot afford them. Of course, there are plenty of problems with solid-state amplifiers, which I'll go into tomorrow.

Headphones Made Slightly Less Complex

Headphones - sometimes also called cans - seem simple. You plug them into a jack, put them on your head, and listen to music.

If only they were.

In reality, there are many varieties of headphones, and just like speakers, they're all slightly different. While they both fit on your noggin and make sound, the difference between a pair of Sure E3Cs and some Stax electrostatic headphones is huge.

Thankfully, there are a few things that can make deciding the right headphones easier. There are really only four types, and variations upon them: open-back, closed-back, in-ear (earbuds), and electrostatic. In addition, they all have several varying characteristics which much be taken into account.

The standard-issue pair of headphones is "Dynamic" - it has a magnet and a cone and a little coil, and works just like a tiny speaker. This single driver produces a full range of sound - hopefully, from 20hz to 20khz, at least in theory. However, much like any other speaker, different headphones have different frequency response - some have a far better range than others.

However,because they're so close to your ear, headphones don't need to make nearly as much sound, and use a tiny amount of power. As a result, a pair of headphones' impeadance is usually much higher than that of normal speakers - usually between sixty and six hundred ohms. Headphone impeadance and sensitivity are both important factors in deciding the right headphones for your application - a pair of 600 ohm headphones simply won't be as loud as a pair of far more sensitive 60 ohm headphones on the tiny voltage output of an iPod.

Of the four types of headphones, closed-back are generally the most common. They have a small chamber on the other side of the driver from your ear, and hence do a very good job of eliminating outside noise. Though small headphones do exist, the lack of a good seal around your ear generally results in much poorer sound quality, and as a result, most high-end headphones are very large with big cups that fit over your ear. Some popular examples of these include Beyerdynamic, AKG, and Sennheiser.

Another, somewhat less common, type are open-back headphones, which lack the outer chamber. While this can help eliminate back resonance and, as some claim, distortion, the lack of a rear chamber results in a lot more outside sound getting through. Popular examples of these are the Grado SR60's and SR80's, which have won a variety of accolades for high-quality sound at a low pricetag over the years.

Of course, a good pair of cans is an inherently bulky object. Earbuds work slightly differently, vibrating a small "plug" that is sealed in your ear. (As a rule of thumb, proper earbuds will work much better than pseudo-earbuds that only fit loosely in the ear.) Because they fit snugly in the ear, well-made earbuds can block more noise than any other kind of headphones. Excellent earbuds can be had from Etymotic Research, Sure, and several other manufacturers.

Finally, there are electrostatic headphones. With the exception of oddball electrostatic-hybrid headphones like the AKG-340s, these headphones require high-voltage sources - also called "energizers" - to create the electrostatic charge necessary for them to function. In addition, they're also highly inefficient, requiring far more power than any other type of headphones.

On the other hand, electrostatic headphones can have far better high-frequency response than any other type of headphones, and can dodge many problems with resonance or energy storage found in most dynamic headphones. While not portable, electrostatic headphones are regarded by their owners as far superior to most loudspeakers - then again, there are many others who disagree with them.

Commentary.

This commentary brought to you by Sinfest.net's Tatsuya Ishida, and IRC chatrooms.

I'll post something more useful later today.

Replacing Speaker Surrounds

Well, I need to sleep, so I suppose it's time for more filler, eh?

Speaker surrounds are the bits of flexible material that join the cone - the part of a speaker that makes noise - to the frame. They must be flexible to a precise degree, as the resistance of a surround can make a huge difference to how a driver performs.

While not so common today, several varieties of foam rubber were very popular for use as surrounds, and could be found on almost all speakers, from the worst to the best. As opposed to earlier solid-rubber and cloth surrounds, they were much less resistive, and were far superior sonically.

The problem is, though, that these foam surrounds degraded quickly, and as a result many fine old speakers are useless because the surrounds are gone. Without a surround, the driver no longer is usable, and a perfectly good speaker goes to waste.

However, so long as the rest of the speaker has not been damaged by rubbing, the driver is repairable - just add new surrounds. While having the procedure done by a professional is not a bad idea, it's not terribly difficult to replacee speaker surrounds, and it's a great way to get a terrific deal on speakers - many really excellent old speakers are viewed as worthless simply because people do not know how to do this simple repair.

http://www.speakerworks.net/kits.html

How SPL works.

Sound is a funny thing. The loudness of a frequency - as we percieve it - is not related to its actual power at all, and it's not even directly related to the amount of power used.

SPL is a measure, quite literally, of the pressure a sound wave exerts - how loud it is. The unit of measure is the Bel - or, more commonly, the decibel, or 1/10 Bel. Louder sounds, of course, exert more pressure than softer sounds. However, SPL is not measured linearly - it's logarithmic.

Every time a signal increases in strength, it increases by 3 dB. To make your stereo 6 db louder requires a whopping four times as much power to the speakers - give or take. This also means that a seemingly small difference in efficiency - the amount of sound produced at a given amount of power, measured in dB at one watt at one meter - can make a huge difference: A 91db/w efficient speaker will produce 100db at one meter using eight watts of power, while an 82db/w speaker would require sixty-four watts - a substantial increase, indeed!

However, making your stereo twice is loud is not so simple as doubling the power to the speakers - human ears don't work that way. Instead, we percieve a doubling of loudness every time the signal strength is increased tenfold - or, in other words, a 10db increase.

This is very important for subwoofers and other highly inefficient speakers - in a stereo where only twenty watts go to each of the 91db/w efficient tweeters, the 84db/w subwoofer requires two hundred watts to keep up. This is also why seemingly tiny differences in loudness can mark the difference between a car stereo and an electrical substation.

Of course, distortion of almost all amplifiers is inherently lower at low frequencies, and subwoofer amplifiers - usually built-in as "plate amps" - can be of a much lower grade than the other amplifiers in the system without a decrease in sound quality. This is especially important for class-D amplifiers - while a high-grade class-D amp is fine for any application, lower-quality class-D amps' distortion can be awful at high frequencies, but is nearly unmeasurable at the low frequencies used with subwoofers.

Car Stereos 101.

-NOTICE-

I am not infallible. If you have brands you'd like me to add to the lists, or think I made a mistake - leave a comment!

While I'm hardly an expert on car stereos (seeing as how I don't own a car), I can at least comment on them from what I've learned over at DIYmobileaudio.com, and hopefully save people from the agonies of a lousy-sounding or overpriced car stereo.


1. Subwoofers are not everything. You will not get better sound quality from a subwoofer, except for at very low frequencies. Strictly speaking, a car subwoofer is unnecessary - some unusually well-built mid-woofer/tweeter combos can do the full range from treble to bass, just like in a home stereo.

Sadly, it's true that it's much harder to get nice perfectly-sized ported cabinets in the kickpanels of your econobox. Bass response is sacrificed for convenience, and a subwoofer is often even more necessary in a car than in a home.

2. Louder is not better. Simply because something is very loud, does not mean it sounds better than is very soft - strictly speaking, a pair of Beyerdynamic headphones put out a lot less noise than do, say, a cheap pair of speakers from RadioShack, but the Beyerdynamics sound a lot better.

Many high-end systems don't use much power at all, and are not really all that loud. A solid 50wpc reciever will go miles farther than 5,000 watts of cheapness.

3. More power is not necessarily better. Amplifiers are measured by distortion specifications, not by how many watts they can put out. In fact, better-quality amplifiers - those heavily biased into class A/B and which inside look oddly similar to a high-end home audio amp - inherently have less power output than a crappily-made monstrousity.

4. Cheap components rarely live up to spec. While a cheap amplifier rated for 3,000 watts might produce that amount of power for a brief moment, that moment would be the tiny fraction of a second while the "magic smoke" is let out. On the other hand, a massively expensive amplifier - say, a Sinfoni - will put out its rated power 24/7 day after day without batting an eyelash.

5. Make sure you have the drivers placed properly. Strictly speaking, the placement of the mid-woofers and tweeters is just as tricky as the design of a standard loudspeaker - except slightly harder, because normal speakers generally give a larger degree of freedom. Badly-placed tweeters and mid-woofers will cause a sonic nightmare.

6. Make sure you have a good install. Improperly-mounted drivers will cause nasty buzzing, rattle, and simply not sound good. In addition, mid-woofer enclosures must be heavily damped to keep your doors from buzzing like bees.

Furthermore, car audio cables, due to the low voltage, must pass a far greater amount of current than normal stereo equipment. If you don't know what you're doing, you'll likely end up with a massive fire. Be very careful of how your equipment is mounted, and make sure that all connections are insulated. Or, better still, have a professional do it.

7. Check your configuration.
There are half a million ways to wire a car stereo - but make sure that you've got an appropriate crossover, or a well-calibrated active crossover. Lower-quality high-power amps go on the subwoofer; higher-quality lower-power amps should go on the mid-tweeters.

Coaxials and "component" (mid + seperate tweeter) sets are both good, but the nature of the crossover can make some better in certian placements. Experiment - and audition - for best results.

8.. This is likely the most important of all: Get "high-end" equipment. While cheap junk might be loud, a quality setup will simply sound better.

Brands to look for:
-MB Quart
-Vifa
-Seas
-Peerless
-Ascendant
-Adire
-LPG
-Zapco
-Dayton
-PPI
-Rainbow
-Pioneer (For head units)
-Aurasound
-Morel
-Dynaudio (warning - OVERPRICED!)
-JL (I'd avoid the coaxial mid/tweeters, though)
And many more.

Brands to avoid:
Sony
Boss
Pyramid
Power Akoustik
Crunch
Pyle
Craig
Jensen
Rockford
Lanzar
Audiovox
Kenwood (except for amps)
Hifonics
Kenford (similar name - cheap crap!)

There are plenty of exceptions to these lists, but you'll be happier with better-quality components, no question. Yes, you'll need to spend a little more - but then again, a professional install's not cheap either!

Speaker placement: The cheapest upgrade of all. Also, geometry!

Good placement of speakers can make a huge difference in sound quality - and it won't even cost you any money!

Even better, you'll find a use for all that pointless geometry you learned in high school.

Here are a few general guidelines.

1. Make sure you keep speakers at least 2'-3' away from walls. With the exception of a few home-theater designs, speakers are generally intended to be used away from walls, which can act as an extension to the front of the speaker, or baffle, and affect frequency response, usually by creating a funny peak in mid-bass frequencies.

Conversely, some speakers are meant to be wall-mounted. If they are not, the reverse will happen - the much, much smaller effective baffle will reduce midbass performance, and adversely effect sound quality.

2. Make sure that the distances between you and each speaker are the same, and that the speakers are the correct distance apart. Stereo (and 5.1) sound is mixed as if the microphones were a given distance apart. If the speakers are not the same distance apart, it won't sound as good.

Needless to say, speakers should also be the same distance away from you - if they're not, the music will be out of phase, and one speaker will appear to be louder than the other. While it's possible to compensate by adjusting the balance, you're better off just making them equidistant from you.

Place speakers in an equilateral triangle for listening to music - the distance between each speaker and yourself should be equal to the distance between the speakers.

However, Dolby HT recordings are intended for the speakers to be closer together - for 5.1, the triangle is a 45-degree isosceles triangle. As a result, the distance between the speakers should be equal to 3/4 the distance between each speaker and you.

4. Toe-in is your friend. While having both speakers directly forward is common, better performance can sometimes be had by moving them so that they face inwards (towards you) a few degrees. They should'nt necessesarily be pointing directly at you, though - experiment for the best results.

5. There's an old trick for subwoofer placement that I've found works pretty well, odd as it is. It works best for down-firing subwoofers; front-firing subwoofers should generally be placed between the two front channels.

First, move the main viewing/listening chair over. Place the subwoofer where the chair once was, plug it into an audio source, and turn it on. While not my first choice of music, I've found that 50 Cent is a good choice for this, as many of his tracks have a somewhat bloated bassline that is very audiable.

Then, move around on the floor, keeping your head close to the ground, until you find a place where the bass seems to be coming from everywhere - this is the correct place for the subwoofer. Replace your head with the subwoofer, and return your head to the correct position.

If you did this right, you should have the same sense of being surrounded by bass in your listening chair as you did on the floor. Of course, this method is not foolproof, but it beats randomly shuffling your sub about the floor.

6. Adjust the crossover point.

Often, HT recievers and powered subwoofers have an adjustable crossover point. Different speakers should be crossed over to the subwoofer at different frequencies for best results, and tinkering with these two frequencies can help keep nasty bumps and dips from appearing in the frequency response.

Commonly, non-HT speakers are designed to work down to about 50hz, while average HT subwoofers are designed to work below 100hz. A bump between 50hz and 100hz may occur, which can cause a "bloated" sound.

So, I'm building some Modula MTs

The RS150/Neo3 project I'm working on is of massive scale - I'm trying some techniques for cabinet damping that can give all the benifits of open-baffle speakers without any of the disadvantages. Needless to say, this will not work properly at all, and in the two years I'm liable to spend making these work, odds are I'll want something to listen to in the interim.

Enter the Modula MT.

Photo and awesome instructions courtsey of :
http://mysite.verizon.net/res6vgmm/danspage/id8.html

The Modulas are pretty much standard-issue 2-ways - one woofer, one tweeter. However, they're notable because they feature some of the "Refrence" series of drivers from Parts Express' Dayton house-brand of drivers. The tweeters, made by Usher, share many design aspects with Scan-Speak tweeters costing triple the price, and the same goes for the aluminum-coned woofers, which are almost as good as the Seas Excel series of metal-cone woofers.


While not exactly anything fancy, the Modulas are a solid design using parts that, if the testing data is accurate, are better than they have any right to be. They're simple, too - while not exactly foolproof, they're much less finnecky than transmission lines or horns, and the design is not complex. The parts are easily purchased from one place, too, and there are many guides to their construction , such as Dan's excellent blog (shown above).

While I'm not nearly in the same class as Dan for woodworking ability, I hope to offer something even more valuable: Step-by-step instructions on construction, and tips on cutting the costs down from his hefty $300 total. While I'm cheating (I'm buying some spare drivers from assorted people for only $125 total) a bit, I hope to keep the total cost at a very reasonable $175 or less.

What to look for in a pair of speakers.

First, much apologies for the lack of a Saturday article. My bad.

Anyway, most people don't want to build a pair of speakers themselves. For some, it's too daunting a task; others don't have the time and energy or simply have no place to do so.

Well, there's no shortage of commercial speaker offerings, some better than others. But what to look for?

1. Weight. While hardly an accurate measure of quality, a speaker with thin walls, cheaply-made drivers, small magnets, and a simple crossover will weigh much less than a well-made speaker. If you can comfortably juggle speakers, they're probbably not very good.

2. Driver type. Cheap speakers often use mylar speaker cones, and have obviously shoddy construction from a cursory glance. Better speakers generally use drivers made by major OEMs, or in-house drivers of obviously good quality.

Things that should be looked for are proper dome tweeters instead of mylar or piezo tweeters, and quality-looking woofers - it's not hard to tell the difference with the grille off. Remember, paper-cone drivers aren't necessarily better than aluminum- or kevlar-coned drivers - just different.

In addition, many cheap speakers will often use a single driver. While functional, these speakers are generally inferior to proper 2-way designs, and I do not reccomend them.

3. Cabinet resonance. If the cabinet is poorly made and resonates like a drum, it will give sub-par performance. Conversely, a well-made, well-braced cabinet can positively affect sound quality.

4. Sound quality. If you don't like the speakers, you don't like the speakers - they won't magically sound better with more expensive wire, or a new reciever. Just because a speaker costs more or is "better rated" does not mean you will enjoy it more than a less expensive speakers.


And now for a few tips on buying speakers:

1. Bring your own CD. Many vendors - especially Bose - will use CDs especially tailored to bring out the best in their speakers. Your own music, however, may bring out faults, like rough frequency response or low-quality bass, which are disguised by the salesmen. If your choice of test music uses very high and very low frequencies, so much the better.

2. Test in your own environment. If you're using speakers in a tiny room, they'll sound very different from in a huge concert hall - and vice versa. Wall-mounting speakers can vastly alter frequency response, as can using different types of stands.

3. Compare directly. An A-B speaker switchbox can be had for $12 at RadioShack, and will let you compare directly one variety of speaker against another. Many vendors allow in-home trials, and this is a good way to compare one speaker against another.

4. Ignore the manufacturer entirely. It's easy to be swayed by slick marketing and fancy design, but a good, solid 2-way will often come out on top in the end. Remember, it's not what's "best" that matters, but what you enjoy listening to the most.

A few brands which I can reccomend:

-Paradigm. They have a well-deserved repuation for solidly-built speakers at a reasonable pricetag. The Paradigm Atoms are not the most attractive speakers, but they use good-quality woofers, tweeters, and crossovers, making them superior to speakers far more expensive - you can't go wrong with Atoms.

-AV123. This is a vendor of high-end speakers good for both home-theater and music, most notably the $1,800 a pair Strata Mini, a 3-way planar-hybrid with integrated subwoofer. While not cheap, you get what you pay for.

-Bowers and Wilkins. Strictly speaking, this old-school manufacturer started making monitors for the BBC, and have been in the buisness longer than just about anyone. While nothing they make is strictly speaking bad, all of it tends to be very expensive - the 800 series will cost you almost as much as a small car.

-Hsu Research. While their HT speakers are nothing special, the Hsu line of subwoofers are very well made, and not unreasonably priced.

-Velodyne. Another good manufacturer of subwoofers.

Connections for Dummies

There are many varieties of connections between audio components. Some are better than others, and while they may look similar, it's important to know the difference. Using the wrong connection between audio components, also called an "interconnect", will cause a loss of signal due to impeadance mismatch at best, and at worst cause damage to one or both components.

The most common type of connection is between "line-level" components, and usually uses RCA plugs. These connections are ordinary sine waves with an amplitude of roughly one volt, though in car audio equipment this may vary. These are basic connections which take analog audio - usually before volume adjustment, and are sometimes used for video, too, as is shown in the left/right/video "composite" connection shown below. (Red is almost always right, white is almost always left, and yellow is almost always a TV connection - though they're all the same cable.)

In addition, there are also "balanced" connections, which feature two leads and a ground, usually intertwined. Because the two "hot" leads are exactly out of phase, any RF is almost entirely cancelled out. For this reason, balanced connections are very popular for "pro" audio usage and in cars. These usually use a three-connection XLR plug.



Another type of common connection is the S/PDIF digital audio link. S/PDIF is the traditional format of connection between digital audio components and DACs, and can carry multiple channels of audio with a single cable. It's generally advised to use one of these to connect your DVD player to your home-theater reciever, and they're the method of choice for the use of external DACs with a CD player (in this case, you bypass the internal DAC in order to use one of higher quality.)

While S/PDIF uses RCA plugs, the cable itself has a different impeadance, and so it is strongly reccomended that you do not use a normal RCA interconnect for S/PDIF connections. The impeadance mismatch will cause signal loss, which will lower the quality of a digital connection.

Digital audio in S/PDIF format may also be transferred through an optical connection, often called a Toslink connection. These are featured most commonly on Sony audio equipment - most notably MiniDisc players - and the Apple G5 and Mac Pro.



While functionally the same, digital optical cables have a few advantages and disadvantages. First, because they use light instead of electricity, they're totally immune to RF noise, such as that produced in an engine. However, the optical cable, made of glass or plastic, is much more fragile than a stranded copper-wire cable, and if the ends become scuffed or dirty on either the jacks or the plugs, it will cease to function properly. In addition, these cables are generally a good bit more expensive than S/PDIF cables.

And remember, folks - you might just find me on Speakchat.

Digital audio and you.

Most CD players sound like junk compared to a good turntable, it's true. They're noisy, fuzzy, and just plain unpleasant.

But that's not because of the quality of compact-disk audio. It's because of the player.

Contrary to popular belief, not all CD players are created equal. Unlike a turntable, which converts vibration in the stylus - through a sort of microphone - into an electrical signal, a CD player instead must deal with a constant input of digital data which must be converted to analog in real-time. Most CD players have three parts: The transport, or pickup; the digital-to-analog converter, or DAC, and the output stage. The transport is a mechanical device containing a motor to spin the disc and a laser to read the CD; the DAC turns the digital signal into audio, and the output stage sets the gain and output impeadance to more usable levels.

The first source of problems is often within the optical pickup on the transport. Each "stripe" of data on a CD is only a fraction of a millimeter wide, and the laser which reflects off of it must be very precisely placed. If the laser pickup is unable to read parts of the CD, that data - and hence, music - is lost.
While a CD player is able to by design able to "smooth over" any missing data, large holes will in turn result in reduced quality. While this is not a problem for most modern CD players, a cheap transport in a cheap CD player (not necessarily an old one) will reduce sound quality.

The most common problem, however, is with the DAC. Digital audio is converted using Nyquist's Sampling Theorem, which essentially states that an analog signal can be turned into data by taking its level on a regular basis. Compact disc audio is 16-bit, and hence has 65,536 possible output levels, which are varied between to create an analog signal. The signal changes level over 44 thousand times per second. Both of these are in excess of what most people can discern - but this is meaningless if not all of it is used.

One of the most common tricks for lowering the price of a DAC is "oversampling". By sampling the frequency twice as fast, it's possible to replicate a voltage at double the actual level of resolution (say, 1.5 volts ) by quickly switching between 1 and 2 volts at double the normal sampling speed. While this can do good things for signal quality for high-quality DACs that oversample at an effective 20 bits (standard 16 bits - but eight times as fast!), many cheap DACs are often just 12-bit DACs set to oversample to an effective 16 bits.

In addition to oversampling, some DACs are simply of low quality. These DACs use poor-quality parts or inferior design, and simply do not sound very good. As a rule of thumb, cheap electronics have poor-quality DACs, while better-quality electronics have better-quality DACs. There are many different varieties, though Texas Instruments makes some of the best.


While even relatively inexpensive transports often are more than adequate, built-in DACs are often of low quality in many CD players. AS a result, many CD players sport external S/PDIF digital audio connections for use with recievers that have on-board DACs, or discrete DAC modules. If you have an older-model CD player, an external DAC may be a valuable upgrade.

Finally, it is hard to ignore the output electronics. Some CD players use cheap op-amps and low-quality power filtering, while others use high-quality op-amps and well-filtered power to reduce noise and hum. While it's generally unnecessary to purchase an external power conditioner, a cheap CD player will often pick up more noise than a well-made player.

Yet More Helpful Links

Well, I'm in a bit of a crunch, as I need to finish some papers to turn in before the end of the quarter. Hence, more semi-lame filler. More verbose audio goodness should, however, follow after the break.

The following are excellent places to visit if you need help with speakers and audio, and I highly suggest you check them out.

1. Speakchat
Speakchat.net is home of the Speakchat java chatroom. (It's not actually IRC, if you're wondering.) While not the most popular of chatrooms, it's the hangout of a few extremely knowledgable individuals, including WmAx and AndyG. Just click the "chat" button in the upper left, and you're done!

2.DIYaudio
The DIYaudio forums have been for years a major center of all DIY audio building and design. Wether you're into single-driver speakers or complex class-A solid-state amplifers, you'll find a variety of experts on it here. Also featured is a sub-forum dedicated to the excellent work of Nelson Pass, who himself posts there on a regular basis.

3. Audiokarma
Audiokarma is the home of a lot of old-school audio enthusiasts. If you want information on your vintage Halfler amp or need to repair your Pioneer HPM-100's, this is the place to go. It's also a frugal audiophile's paradise - with a little work and combing of Goodwill stores, it's possible to get stereo equipment superior to that sold at Best Buy for a fraction of the price.

4.DIYmobileaudio
DIY Mobile Audio is the hangout of car-audio enthusiasts who do it the right way: using high-quality drivers and custom crossovers. If you want to get a serious sound system in your car without a massive drain on your wallet, this is the place to do it.

5.Parts Express "Tech Talk"
While less formal than the more complex bulletin-board system employed by the other listed forums, Tech Talk is a useful resource nonetheless. If you need a quick question answered - or just want to look at other people's designs - this is a great place to go. Also easily found is information on Parts Express' clearance drivers, and assorted very inexpensive speaker designs based around them.

Finally, feel free to E-mail me any questions you may have. I'm still learning as I go along, but I'll help to the best of my ability.

And now, my first original speaker design!

I recently snagged a pair of Neo3PDR tweeters for $60. While the Cryolites are supposed to be excellent, I'd like to go for something a shade smaller.

As a result, I'm going for the Dayton RS150 woofers and active 8th-order crossovers, courtsey of a pair of Alesis amplifier modules. Distortion should be even lower than the Cryolites, and thanks to the impressive off-axis performance of the RS150 and Neo3PDR, I won't need to worry much about a "sweet spot".

To go with them, I'll hopefully get a subwoofer of some sort. The end result will, hopefully, be a system I won't want to upgrade anytime soon.

(Yes, I'm lazy and not posting much today. I need to go to bed.)

So, what's this amplifier jargon mean?

Amplifiers are a vital component - while the loudspeaker reproduces the sound with a varying degree of accuracy, a speaker can only be as accurate as the signal sent to it. While there are an endless supply of meaningless buzz-words attached to almost all amplifiers, there are meaningful numbers as well.

Perhaps the most commonly flaunted number is "watts RMS". This is, very simply, a measure of power - in other words, what would happen if the signal were rectified to DC from an AC sine wave, and the wattage (volts multiplied by ampres) were measured. While there are several other forms of measurement also employed today, such as "music power" or "PMPO", these are almost always meaningless, and should be treated as marketing baloney.

An amplifier's RMS output is usually stated at a given impeadance - for example, 120w into 8 ohms, or 200w into 4 ohms. This is basic electronic physics - current is equal to the voltage divided by impeadance (ohms), and if a given voltage is applied to half the impeadance, the resulting current - and hence, wattage - will double. This only occurs in the best of amplifiers, though: with the exception of some massive Nelson Pass designs, inefficiency and internal resistance within the amplifier - if not simply the internal power supply - will limit output to a bit less than double.

Some cheaply-made amplifiers are only capable of driving an 8-ohm load. While it's usually safe to use them with a 6-ohm load (common on some home-theater speakers), a 4-ohm load will cause too much current to flow through the output transistors on the amplifer - which will, in turn, cause it to overheat and die.

As much as it is flaunted, raw power is not a measure of quality. Much like speaker drivers, amplifiers also have a measurement of distortion - but they must also include residual noise from the power supply and crosstalk. This is abbreviated to THD+N, and is the benchmark for audio quality.

However, there are several tricks in measurement to look out for. First, almost all but the highest-quality amplifiers distort more at higher frequencies; as such, the THD+N is measured at a very low frequency, and this may give misleading results - especially on some cheaply-made class-D amplifiers. Secondly, distortion will often increase as the power output increases - make sure that the THD+N rating is at no less than 1/10th the rated maximum output power, or roughly half maximum volume.

DIY Loudspeakers Part 4: Return of the Boxes

While speaker drivers and crossovers are very important, they're generally quite useless without a box to put them in. In fact, a woofer's frequency response is determined largely by the box it is used in - without a box, they won't work very well at all.

There are basically five kinds of boxes: Sealed boxes, ported boxes, horns, transmission lines, and open-baffles. Each performs very differently, and each has its own benefits and hindrances.

Sealed boxes, like the name suggests, are air-tight boxes into which drivers are placed. Because there is no way for back-pressure created by the driver to escape, these are sometimes also called "acoustic suspension" speakers. They have a -12db/octave roll-off below the tuned frequency, although this will vary between box and driver. In addition, the lack of other resonant objects aside from the air in the box eliminates potential sources of distortion.

Ported boxes are similar to sealed boxes, except that they have a hole or tube - a "port" - that resonates at a pre-determined frequency. Because this "port" allows a point of resonance of a lower frequency than the box itself, it can help increase response at low frequencies. However, the roll-off is a steep 24 decibels per octave - eliminating some very low frequencies entirely. Furthermore, the port can cause unwanted resonances in the driver, and may cause distortion if not designed properly.

A horn works a lot like the instrument which shares its name: Small at the end with the speaker driver, and large at the other. However, many horns incorporate resonating chambers and reflective sections to compensate for frequency response, making them far more complex than a simple expanding pipe.There are generally two variants of horn: Front-loaded horns, which go on the front of the driver and face towards you, and back-loaded horns, which go behind the driver. While front-loaded horns - which more directly affect the sound which travels to your ears - can cause distortion if built improperly, they are also generally very, very efficient - they work like an old-fashioned megaphone, which despite having no electronic parts can make your voice effectively louder.

A transmission line works like a horn, except backwards. The general concept behind a transmission line is that they are in essence a tube behind the driver, stuffed with a filling- usually some sort of fiber-based fluff. The longer the wavelength, the more fluff a single quarter-wave of the frequency will have to travel through,. The physics and design of transmission lines is very complex, and requires some sophisticated mathematics for modelling them - however, the bass performance of these can be impressive indeed.

Open baffles really are not boxes at all. Instead, they're just a flat plate - a "baffle" - that allows for reflection of sound waves off of it, and prevents vibrations emanated from the front from being eliminated by vibrations from the back. Open-baffle speakers are generally poor in terms of bass performance, as low frequencies have a wavelength long enough that it would require a massive baffle to prevent bass from self-neutralizing. However, so long as they are placed a suitable distance from walls, the lack of back-resonance can eliminate a large amount of distortion. For this reason, open-baffle speakers are very popular, and a mid-woofer in an open baffle is often combined with a woofer in a ported box.

Tomorrow: Baffle step, and what exactly is, anyway.

The Budget Challenge, Part 1

Recently, I've blown a massive amount of cash on speaker drivers. (When I try something, I always seem to go overboard. It's a fault of mine.)

However, most high-school students (let alone grad students), interns, and thrifty individuals cannot afford the price of even the cheapest of DIY speakers. While a $120-a-pair design might outperform $200-a-pair commercial speakers, there's not much in the $60-a-pair bracket.

While Zaph's single-driver B3S design is an excellent design with a sub-$50 pricetag, the low maximum output and lack of bass make it less than appropriate for "rocking out", as also applies to many other small single-driver designs. And buying "buyout" parts is also impractical- good as they might be, they're not going to be very useful if there are no pre-existing examples to work off of.

As a result, I'm starting a competition of sorts for a reliable, easy-to-build, and cheap speaker design. The catch is that they must have a total driver cost of less than $50 total, and that the drivers must be commercially availible - NSBs don't count. The winner wins a yet-to-be-disclosed grand prize, while the 2nd place winner wins a Linksys WUSB11 wirless adapter. (I have a spare.) 3rd place winner wins a collection of singles on CDs that I have laying around.

So, the rules are as follows:

1. Total driver cost of $50 or less. (A little more than $50 is okay.)
2. Simple crossovers. No more than 2nd order, if possible - this helps keep the cost down.
3. No single-driver speakers, unless they're usable down to 60hz.
4. Reasonably high output level - preferably at least 100 db/1m before clipping.

Ideally, I'd like to see some transmission lines or towers - good bass is priority.

And now, for a few reccomended drivers:

Woofers:

1. Silver Flute W14RC25($17)
This woofer was featured by Zaph in one of his low-end designs, and while I can't tell you much other than that it was a transmission line, I recall that it's been used successfully in another design with the Hi-Vi K1 tweeter ($9).

2. Peerless 830392 5.25" woofer ($10)
Madisound's had these in stock for ages. Peerless is a good brand - for $10, how can you lose?

3. Hi-Vi W4-654 woofer ($18)
While this might be more appropriate for a smaller speaker, its large frequency range means a simple crossover.

4. Dayton DA175 ($18)
This driver offers good performance - and good bass - at a very reasonable price. Far, far better than the dayton "classic" woofer.

Tweeters:

1. Hi-Vi K1 ($9)
An all-around decent performer - and cheap, too!

2.Aurasound NT1-204-8D titanium-dome tweeter($8.50)
This seems to require a somewhat high crossover point (~3khz), but is supposed to perform well.

3. Vifa D19TD05 3/4" soft dome ($15)
I think that this is similar to the tweeter used in the Paradigm Atoms.

4. Vifa D20TD05 3/4" soft dome ($16.50)

5. "Shielded Soft Dome Tweeters" (A.K.A. Meiloon tweeters) ($7.50)
These were used to great effect on the PE board - they're supposed to be quite good.

6. Dayton ND20FB 3/4" soft-dome tweeter ($5)
This driver tweeter offers nice performance at a very low pricetag...above 5khz.

DIY Loudspeakers Part III: Crossovers

While a loudspeaker driver may be excellent at what it's designed to do, very few speaker drivers can cover the full range of human hearing from 20hz to 20khz. As a result, multiple drivers are almost always used in speakers; some for high frequencies, and some for low. There are endless permutations on these; some speakers use a tweeter that can handle the midrange, and hence "cross over" to the woofer at a low frequencies, while others apply a midrange driver to cover the area between where a large woofer and a tweeter can perform.

Of course, you don't want low-frequency signals sent to the tweeter, nor high-frequency to the tweeter - in this way, you can have them produce sound in the areas where they distort the least. This device, which determines where the signal "crosses over" from a low-frequency driver to a high-frequency driver, is hence referred to as a "crossover".

Because even the best speaker drivers work better in some frequencies and worse in others, a crossover can make or break a speaker. There are numerous examples of half-cocked DIY projects using $160 Scan-Speak tweeters and $300 Eton woofers that sound awful because the designer chose a crossover ill-suited to the components, and speakers using $17 woofers and $9 tweeters that sound marvellous because the designer was able to use the best parts of both drivers. In addition, a careful crossover design can help correct for artifacts in frequency response - dips and peaks can be neutralized.

Most crossovers are passive devices, having no components that require any power. These usually consist of capacitors and inductors in various configurations of series and parallel to determine functionality.

While the electrical engineering behind these devices is somewhat complex, the simplified version of it is as follows: Capacitors will reduce power moving through them 75% every time the frequency is drecreased by 50%, or, in other words, they reduce volume from the speaker driver by six decibels every time the frequency is moved down an octave. Inductors work much the same way, except backwards, reducing power moving through them 75% every time the frequency is decreased by 33% (6 decibels per octave down). Past a given point, the decrease in power is so tiny it's almost immeasurable - hence, capacitors are useful for sending high frequencies to tweeters, and inductors for sending low frequencies to woofers.

Inductors are measured in Henries or Micro-Henries (uH), while capacitors are measured in Farads or Micro-Farads (uF). The value of these components determines what frequencies they will let through, and what they will not - a larger inductor's effects are noticeable at increasingly low frequencies, while a smaller capacitor will attenuate the frequency at much greater levels. In other words, bigger inductors block lower frequencies, while bigger capacitors let through lower frequencies.

However, because two capacitors or inductors wired in series will simply act as a single inductor or capacitor, they are usually combined: For example, a capacitor may be used in series with a tweeter, followed by an inductor in parallel. The capacitor blocks low frequencies, and what is not blocked by the tweeter will then bypass the tweeter through the inductor. As a result, 12db per octave is lost. The number of components corresponds to the resulting drop per octave; a two-component crossover as above is called a "second-order" crossover with a 12db/octave drop, while one with an additional capacitor after the inductor would be a "third-order" crossover with a 18db/octave drop.

In addition, capacitors and inductors can be used to fix problems in frequency response. For example, the Bohlender-Graebner Neo3PDR tweeter, which I am using in a project, has a frequency response peak around 3khz. As a result, most people put in parallel with the tweeter an inductor and capacitor : The capacitor allows through frequencies from about 11khz up, the inductor allows through frequencies below 9khz. Between these two points, the frequency is decreased by 6db/octave up from 9khz and down from 11khz - just the right amount to eliminate the peak.

I should stress that crossover design is tricky, and I, as a newbie myself, strongly recommend that you consult someone more experienced than yourself - or, better still, use a tried-and-true design, such as I provided links for yesterday. Designing a crossover by hand is very difficult, and while most good speaker design programs include excellent crossover design functionality, these tend to be both expensive and difficult to use.

And on the 5th day, he did get lazy, and posted links.

No more not-quite-in-depth, poorly-worded information today, folks! I suffer from a bad case of friday-itis.

Anyways, I figured I ought to bring up something that everyone can appreciate: Aggregated, organized, and easily-explained links for DIY speaker designs.

Sub-$100:

Zaph's B3S single-driver speakers:
http://zaphaudio.com/audio-speaker18.html
These are single-driver speakers, which means that they're not going to be the all-time best for treble or bass. On the other hand, at under $40 a pair, they're also really, really cheap. They make very nice near-field (i.e, desk or computer) speakers, and are a very good option for HT satellites - especially the rear channels, which rarely carry high treble or low bass anyway.

Zaph's Silver Flute/Vifa combo
http://zaphaudio.com/audio-speaker13.html
This is a pretty darn good design for the money, and Zaph has a reputation for nearly unbeatable crossover design. If you're short on cash, these are hard to beat.

Sub-$200:

The Modula MT:
http://mysite.verizon.net/res6vgmm/danspage/id8.html

The Modula MT is a classic 2-way (woofer and tweeter) speaker based around some high-quality and inexpensive drivers. While some people don't like metal-cone drivers (like those in the Modula) for their resonance at high frequencies, this is a tried-and-true design that works very well for HT or music duty.

Lou's Cryolites:
http://www.lonesaguaro.com/speakers/DaytonRS7/Cryolite.htm
These 2-ways use the BG Neo3 planar tweeter in a design similar to the Modulas. However, the tweeter is very, very different - many people prefer them. Both these and the Modulas are supposed to be excellent - and the price difference is not that huge (about $30), either.

Zaph's Bargain Aluminum MTMs:
http://zaphaudio.com/BAMTM.html
This uses the excellent Seas 27TBFCG in an MTM configuration with two slightly cheaper woofers. They're very efficient speakers, and with a subwoofer, are nigh unbeatable for home-theater use.

Sub-$300:

Zaph's L18/27TBFCG 2-way
http://zaphaudio.com/audio-speaker17.html

This is a 2-way by Zaph using the same tweeter as the BAMTM, but with a high-grade Seas L18 aluminum woofer. Testing has shown that these are over 95% as good as their more expensive Excel-class cousins, but at half the cost - and many builders will testify to this design's quality.

Lou's Zircon towers
http://www.lonesaguaro.com/speakers/zircon/zircon.htm
The Zircon is essentially the "big brother" of the Cryolites, using a more expensive Vifa woofer in place of the Dayton. They're also much larger, being traditional tower-style speakers, but have better bass as a result. I'm afraid I can't give any testimony other than that of the designer, but his other design featuring the tricky-to-use Neo3 (the Cryolites) is extremely popular - and it's hard to go wrong with something which compares well to the $2,000 a pair ACI Jaguars.

DIY loudspeakers part 2: What's all this stuff mean, anyway?

In a standard pair of speakers, there are three parts: The box, the crossover, and the drivers.

Speaker drivers are the objects in the box that make noise - woofers and tweeters. Due to their complex construction, these are almost always purchased pre-manufactured, unlike the box and crossover. While some drivers are definitely of better quality than others, it's important to pick the right driver for the right application - for example, if you want to use a tweeter that only works at high frequencies, it's necessary to use a woofer that can cover the midrange.

A speaker driver's performance is measured in one of several ways, some of which are meaningless, while others are no more useful unless you have a degree in acoustics. However, we'lll be ignoring them in favor of the two most useful: the response graph and total harmonic distortion (THD) graph.

This graph courtsey of Zaphaudio.com - visit it!

This is a response graph for a Seas 27TBFC/G, a very popular, high-performance and moderately priced ($35) tweeter popular for DIY use. A sound spectrum sweep - similar to playing all the keys on the piano from the low end to the high - was done, and the Sound Pressure Level, or SPL, was measured at a set distance. (SPL is essentially a very accurate measure of how loud something is.)
The purpose of a SPL chart is to show how well a driver works as a whole. Because this is a tweeter, the SPL - in other words, how loud it is - decreases rapidly below 2khz, as it is not intended to be used at low frequencies. Above that, it produces more or less the same volume level up to above 20khz. (The very high level of response above 20khz is due to resonance, but you can ignore it - it's largely inaudiable.)

The other important measure of a driver's performance is the harmonic distortion graph. Harmonic distortion is exactly what it sounds like - how much a loudspeaker driver distorts from the audio signal input to it. Expensive drivers generally have much lower distortion than cheap drivers, but all drivers distort differently at different levels - even the best tweeter will not work very well at low frequencies.

Yet another awesome graph from Zaphaudio.com

The above is a THD graph for a tweeter, the Dayton ND20TA ($5). As you can see above, there are several forms of distortion, but it's easy to see that the higher the frequency the tweeter is used at, the less it will distort. As a result, it's strongly reccomended not to use this tweeter below about 5khz.

Tomrrow: Crosssovers, and how they will eat your babies.

DIY loudspeakers part 1: Why bother?

Home-made speakers are nothing new. In fact, at one point in time, almost all audio stuff was built from a kit.

Today, however, there are a bewildering array of pre-built options from the cheap clock radios at Wal-Mart to $10,000 a pair Bowers and Wilkins obelisks.

So, why bother?

To most people, the most important reason would be price. As a rule of thumb, no more than 40% of the cost of a pair of speakers goes to parts - sometimes less, and sometimes more. Even though it's not practical to buy the parts by the thousand as commercial vendors do, homemade speakers can cost over 40% less than their store-bought equivalent - and even less than that if you take the time to find the parts as surplus.

The quality is also an issue. The majority of low-priced speakers - in other words, anything below $200 a pair - are junk. In this price range, however, there are a plethora of designs using low-priced components that make a mockery of what you'll find at best buy for double the price. Because there's relatively little profit in these less expensive speakers, the parts are almost always far, far cheaper. As a result, a thriftily built pair of homemade speakers will generally outperform commercial speakers costing as much as three times as much.

For more pricey speakers, this works doubly so. While it is possible to save only 30% off the price of a commercial offering, this is a big deal when you're using $160 Seas Excel woofers and $180 Hiquphon tweeters. Hundreds and hundreds of dollars can be saved in this way, and because these high-end components are designed to last, they can often be purchased used at a fraction of the retail price.

Others build their own speakers as a matter of convenience - often, certain locations or situations require specialized speakers. Some people desire a line array's movie-theater level punch in their home cinema, while others want speakers able to maintain a high level of quality even at very low volume for use in unusually small rooms. Obviously, there's not much of a market for these sorts of specialized speakers, and if you want some, you build them yourself.

However, more than any other reason, people build speakers simply because it's fun. It's far more rewarding to spend $180 on parts and six weeks on your prized home-theater towers or mini-monitors than to simply drive out to Best Buy and plunk down $600 for something roughly as good. Your speakers will be a reflection of you, exactly how you like them - no more wishing you could get a better veneer, or get just a little bit less treble out of the center channel.

Regardless of your reason, I hope to provide information to everyone - especially Madison residents - on building your own speakers.

The Hitch-Hiker's Guide to Madison, WI: Part One

Madison, Wisconsin is a marvellous place to visit on a budget. While we lack much in the way of youth hostels, there are a variety of places where you can sleep in your car.

Of course, if one is visiting Madison, food is a concern. While portions are large, prices tend to be as well - many seemingly "family-style" eateries are $10 a plate - plus drink - for most of the menu. This will not do for the traveller trying to see the wonders of the midwest on thirty of any dollars per day.

Here are a few of my favorite options for cheap - but edible - food.

1. Bagels Forever.
Bagel chains - you know, those schmucks who want you to spend $2 for a bagel with cream cheese?

Forget 'em. We have real bagels.

The main Bagels Forever is, in fact, a bagel factory - they make bagels on location, and when I say "make", I mean they start with flour, water, and eggs. And, unlike those that are pre-frozen and sold at supermarkets, they're delicious.

And best of all - $0.30 gets you a bagel, and $0.40 gets you a jumbo bagel! $0.50 gets you a can of soda (don't be tempted by the more expensive carbonated beverages - they're not that much better), and cream cheese or peanut butter can be had cheaply, too - but then again, you probbably brought peanut butter packets from some place that was giving them away for free.

Price for a meal?
$0.60 - 2 bagels (I reccomend egg - the protein is yummy!)
$0.40 - packet of peanut butter
$0.50 - drink

Total: $1.50 for lunch.

Alternately, their "Breakfast Bagel Sandwiches" - which are almost identical to those at McDonalds, except made with recognizable eggs, meat, and cheese - are great for lunch. At $2 each, they make a great way to beat the cold.

2. The Maharajah's Sunday Buffet
$7 does not seem like a bargain for a buffet. Anyone can get a buffet for $7.

But most buffets are not this amazing.

As a rule of thumb, expect tureens of above-average tandoori chicken, at least three curries (the saag is not bad at all), and several desserts - which always include the traditional gulab jamun, and often have at least one "dessert of the day", which is generally very complex and would sell for at least $4 a portion otherwise.

The trick with this is to eat no breakfast, pig out at about 1:30 PM (it lasts from 10:30 to 2 P.M, if memory serves) and eat no dinner. $7 ($9 after drink) is not so bad for a day of food.

3. Pizza de Roma
Pizza de Roma is one of my favorite restaurants. It has almost no atmosphere to speak of - while there are some nifty murals that appear to have been unchanged for a period longer than I've been alive, they're spoiled by the endless din of the not-quite-working-properly big-screen TV in the corner - but, trust me on this one, you won't care.

Why?

Amazing pizza.

While the prices - between $2.60 and $4.50 a slice - seem high, a single wedge of pizza is a meal in itself. My particular favorite has vast amounts of eggplant, fresh mozzarella, and basil - real food! - and only costs $4.15 for a meal. The desserts and calamari, while not quite such an excellent value, are also similarly delicious.

If you want to go where the locals go, forget the Nitty Gritty (food only enjoyable when you're inebriated, it would seem) and other such hawked attractions. Pizza de Roma is the place to go.

Also, please leave a tip. These folks work dang hard, and actually heat up the pizza on the spot, so it's piping hot and bubbling gloriously when you eat it.

4. Yummy Buffet

Yummy Buffet is yet another MSG-enfused bad-asian-food extravaganza. Aside from its small side and less than amazing array of selections, it has two notable features: A proximity to downtown madison, and extremely low prices.

$5 for all-you can eat, $3 a pound for take out.

If you're in a huge hurry, just scramble in, load up a styrofoam tray with whatever looks least likely to cause gastrointestinal anguish, and run - $3 is not a lot of money. Or, get snacks for a group.