Naptastic

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===== Overview =====
The Legendary Sound System consists mainly of a highly developed, highly configurable PA system, which can be run on car batteries (optionally tied to a car's electrical system) or on wall-powered amplifiers.

Also listed on this page are hardware and software for making music in my possession.

=== Main Speakers ===
Two four-foot tall, nine-inch wide, 15-inch deep, angled tower line array speakers provide potentially ridiculous amounts of sound from 180hz to 18khz. If all you're amplifying is speech (or the audience is all Mormon) then they should be all you need.

They are built of high-quality 3/4" plywood, covered with 2 layers of truck bed liner and painted black. The drivers themselves are Galaxy Audio Hot Spot Monitor drivers, 5-1/4" in diameter. Each tower contains 9 drivers in a straight line up and down. They are wired three in series times three parallel circuits, for a nominal load of 8 ohms. Theoretically, you could put 900 watts through them, if they were crossed over at 200hz (maybe higher) but that would be a LOT of sound, and I can't think of an application where that would be warranted. Getting 900 watts into an 8-ohm load is a big challenge, too. I don't have any amps that will do that.

If the tower speakers are used for high-fi purposes, they require equalization. At one time, I had access to a DBX speaker management system with automatic tuning, and came up with these recommended settings:

  * F<sub>1</sub> = 2500hz
  * G<sub>1</sub> = -4.0 dB
  * Q<sub>1</sub> = 7.4
  * F<sub>2</sub> = 2500hz
  * G<sub>2</sub> = -3.0 dB
  * Q<sub>2</sub> = 1.6
  * F<sub>3</sub> = 16khz
  * G<sub>3</sub> = 6.0 dB
  * S<sub>3</sub> = 3 ???

=== Subwoofers ===
Six 10" subwoofers provide the bass from 38hz to 200hz. They can reasonably be crossed over up to 500hz, but I find 200hz is what they were designed for, and it sounds better to have the crossover point there than in the middle of the fundamental frequencies of most instruments.

The construction is 1/2" Baltic birch plywood with 1" square cleats to hold everything together. The outer dimensions are 13-1/2" wide, 14" tall, and 22" deep, though planners should give a little more room than that because of the upholstery.

Four of the six are upholstered with black Naugahyde and 1/2" of cotton quilt batting (if memory serves--I'm sure it was 1/2 but it may have been a different material) and the other two are still plain wood, but painted black in all the critical (front) places. If you are using all of the speakers, you can put one of the plain speakers on the floor with an upholstered speaker on one side, one on top of it, and one tower on the other side, and no one will ever know that parts of one speaker are hideous to look at. ;-)

For parade / truck-loaded use, just put the plain speakers on the bottom, which will make the stack more stable and more attractive.

=== Tool set for Making Music ===

The most important and most powerful parts of the sound system for generating sound are the computers. With reasonably up-to-date Linux distributions and a mostly bleeding-edge audio stack, each computer (Hex, my desktop, Leopard, my laptop, and Live, the network server--which should never be removed from service for an audio job!!!) contains a customizable digital mixer with equalization, compression, convolution filtering, and LADSPA and LV2 plug-in support, limited only by CPU power and RAM.

The audio stack is built around JACK2 (formerly JACKmp) to exploit the SMP functions of each computer. The primary application that provides all the actual usability is Ardour 3, the 'six-hundred pound gorilla" of Linux audio processing. It can be configured as a formidable live mixer, with basically unlimited tracks, buses, sends and returns, and the option for all kinds of plug-ins on any or all tracks, buses or sends.

Other software is available, notably Qsynth, though Qsynth does not work with recent versions of JACK, and older versions of JACK don't work with newer versions of Ardour, so for the time being, Qsynth is unavailable.

Other hardware to supplement this system include:

  * RME HDSP 9652 and equivalent RME Digiface digital audio interfaces for Hex and Leopard, respectively
  * 3x Behringer ADA8000 AD/DA boxes for a total of 24 channels in and out--though some channels don't work
  * Behringer Eurorack MX3242x in-line mixer in good condition
  * Numark CDN-90 dual-CD players with pitch shifting, effects, loops, and other great features. (THEY'RE AWESOME.)
  * Lots of microphones and stands
  * Casio digital piano, 88 weighted keys, pretty-good samples
  * Yamaha 5-octave non-weighted keyboard with good synth engine
  * Probably some other things I'm forgetting.