Audio Island & Pattern Juggling

I have added two new categories to the refuge, Audio Island and Pattern Juggling, for the convenience of those interested in a couple of my “off the beaten path” jaunts. I have gone back and retagged a bunch of old posts and will use these tags in the future. Audio Island is basically a catch-all for audio/acoustics/electronics gear, new technologies, observations, and the like. Pattern Juggling is the location for my ramblings regarding the intersection of drumming, co-ordination, art and so forth (for example, the DIY Neuromotor Experiments posts). Audio Island is perhaps a bit obvious, Pattern Juggling less so. In PJ you’re likely to find a little math, maybe some neuro-science, music/art, fine motor control, limb independence and interdependence, and how it all comes together for the drummer or percussionist.
I don’t want anyone to think that Pattern Juggling is aimed only at drummers, though. Anyone, musician or not, can try some of the experiments and tricks that I have/will brought/bring up, and I’m interested in the results of your experiments and trials, musical or otherwise.
Granted, while I am not a renowned expert practitioner of the subject, I trust there will be items to stir your imagination. Who knows, maybe some day, a member of the highly co-ordinated set such as Bill Bruford, Joe Morello, Chad Wackerman, Terry Bozzio, or Vinnie Colaiuta will be cruising the net, happen across our little discussion, and offer some kernel of insight. Well, one can hope anyway…

Audio Island & Pattern Juggling

I have added two new categories to the refuge, Audio Island and Pattern Juggling, for the convenience of those interested in a couple of my “off the beaten path” jaunts. I have gone back and retagged a bunch of old posts and will use these tags in the future. Audio Island is basically a catch-all for audio/acoustics/electronics gear, new technologies, observations, and the like. Pattern Juggling is the location for my ramblings regarding the intersection of drumming, co-ordination, art and so forth (for example, the DIY Neuromotor Experiments posts). Audio Island is perhaps a bit obvious, Pattern Juggling less so. In PJ you’re likely to find a little math, maybe some neuro-science, music/art, fine motor control, limb independence and interdependence, and how it all comes together for the drummer or percussionist.
I don’t want anyone to think that Pattern Juggling is aimed only at drummers, though. Anyone, musician or not, can try some of the experiments and tricks that I have/will brought/bring up, and I’m interested in the results of your experiments and trials, musical or otherwise.
Granted, while I am not a renowned expert practitioner of the subject, I trust there will be items to stir your imagination. Who knows, maybe some day, a member of the highly co-ordinated set such as Bill Bruford, Joe Morello, Chad Wackerman, Terry Bozzio, or Vinnie Colaiuta will be cruising the net, happen across our little discussion, and offer some kernel of insight. Well, one can hope anyway…

DIY Lab Gear: Vibrating String Apparatus

Sometimes I can’t seem to find just the right lab equipment I want for a particular experiment so I design it myself. Such was the case recently for a course I developed and teach entitled Science of Sound. This course is a natural science elective and deals with the physics of audio and acoustics. We start with a few very basic concepts such as harmonic motion. One of the laboratory experiments involves vibrating strings. I like this experiment because students can relate to it as most are at least familiar with guitars and other stringed instruments (the guitar players really like this one). I had some difficulty in designing a good experiment though. The basic idea is to verify the equation for the fundamental vibratory frequency:
VibStrFormula.jpg
where f is the fundamental frequency, l is the string length, T is the tension, and m-sub-l is the mass per unit length of the string.

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Esoteric Audio Cables

I’m just interested in whether this gear is sonically superior or simply audio woo.

A previous post featured a short film about members of the Audiophile Club of Athens and the rather extreme sound systems their members have created. Some members spent in excess of $300,000 to build their systems. You may be wondering just what manner of gear that sort of money would buy, and would it really sound that much better than a more modest (yet still comparatively “high end”) system of say, several thousand dollars. Before we go any further, let me state that in no way am I making fun of the way people spend their money. Heck, I’ve been known to drop some coinage on musical instruments and Kevlar kayaks, things some people find frivolous. No, I’m just interested in whether this gear is sonically superior or simply audio woo.

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Audio Obsession

Who are the audiophile extremists? To what lengths will they go in their search for audio nirvana? Is 230,000 Euros enough, and what do they spend it on?

Regular readers of the refuge know that I’ve got a “thing” for audio and music, and that I’ve had some harsh comments regarding the poor quality audio that so many people tolerate these days in the name of convenience. But what of the other extreme? Who are the audiophile extremists? To what lengths will they go in their search for audio nirvana? Is 230,000 Euros enough, and what do they spend it on? Check out this short film of the Audiophile Club of Athens:

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Super Low THD+N

We’d have killed for gear with the sort of quality now available. I mean that literally. Killed for it. Not necessarily other people (well maybe, in some cases), but animal sacrifice wouldn’t have been automatically ruled out.

On the audio front, National Semiconductor, long a player in analog semiconductors, has announced a couple new op amp families producing a total harmonic distortion plus noise spec of 0.00003%. These devices are aimed squarely at higher end audio applications and also offer a very low voltage noise spec of 2.7 nanovolts per root-Hertz with a flicker noise corner of 60 Hertz. I find these numbers to be pretty impressive, especially considering a starting price of $1.35 per unit in 100’s (up to about $10 depending on package and other details).
During my college days it was something to find devices with THD specs much below 0.1%, and even the best distortion analyzers were at least an order of magnitude above these little op amps. Also, “low noise” devices rarely broke the 5 nV barrier (the venerable 5532 comes to mind) and they almost always had a lower noise corner frequency well above 100 Hz.
In spite of the ready availability of low cost yet high performance analog semiconductors, I am continually amazed at the piss-poor audio quality that some people seem so happy to accept these days (highly compressed MP3s, “phone” audio, cheesy headphones, car subwoofers that are effective at pumping out 70 Hz tones and little else, etc.). We’d have killed for gear with the sort of quality now available. I mean that literally. Killed for it. Not necessarily other people (well maybe, in some cases), but animal sacrifice wouldn’t have been automatically ruled out.
Courtesy of Audio Design Line.

Apple iPhone Guts

Curious about what’s inside an iPhone? Well, the good folks at audio design line have a teardown.

Curious about what’s inside an iPhone? Well, the good folks at Audio Design Line (via EE Times) have a teardown.
Mind you, it’s not like the old days when you could just pop off the cover of your new electronic doohickey and look at the manufacturer’s part numbers on the chips. These are the days of self-branded ICs. So what did the folks at the technology evaluation/investigation company Semiconductor Insights do?

To get inside the chips, SI resorted to decapping, a process that involves immersing the chips in acid to dissolve the outer packaging and then manually scraping away any residual packaging material.

Sounds like fun! Check out the video of SI’s teardown:


I must admit that I had a little sinking feeling after reading this:

Despite the phone’s “external simplicity and serene look and feel, the internal implementation is actually quite complex,” he said. “There are many secondary operations, fastener screws and difficult orientations needed for final assembly, making the manufacture of the iPhone in China a near-must.”

Not only can’t we afford to make socks in the US anymore, it seems we can’t afford to make almost anything that isn’t prohibitively expensive to ship.

Bypass Capacitors

Proper usage of capacitors in audio circuits almost seems to be a black art. This article should offer some insight.

Shifting gears from the usual ranting at the Refuge, I came across a nice series of articles from Audio Design Line on the usage and selection of bypass capacitors in electronic circuits. This is a topic with which my students often seem to have difficulty. There is a nice tutorial on the modeling and behavior of capacitors and some practical info regarding the various types, with strong and weak points for each. One of my favorite bypass tricks is dealt with in some detail; namely placing different types and sizes of capacitors in a parallel arrangement to create a sort of “super cap” that exhibits superior performance when compared to any of the component caps.
Proper usage of capacitors in audio circuits almost seems to be a black art. This article should offer some insight.

The Sound (and Cost) of Worship

If the primary mission of churches is to help people and their communities, don’t you think that the money might be better spent elsewhere instead of making a glorified home entertainment system for the faithful?

Audio is where I spend much of my time, both professionally and as a hobby. In fact, quite a few years ago I used to design public address systems and components (most notably loudspeaker systems and subwoofers). That venture didn’t last too long because I discovered that many people just didn’t care that much about high quality audio and weren’t willing to pay for it. If only I had been born 20 years later.

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The “Inherent Linearity” of Class A Amplifiers?

I’m what they used to call an audiophile. What with folks listening to music on cell phones, low bit-rate MP3’s and the like, it’s kind of out of fashion these days. That is, unless you’re into music production. In that case, you can buy all manner of interesting goodies, including microphone preamps that will set you back a kilobuck and loudspeaker cables that could pay a semester’s tuition. Unfortunately, just as it was true for hi-fi enthusiasts 30 years ago, there’s a lot of misinformation floating around in the semi-pro or “prosumer” music field regarding audio circuitry.

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