PAlien Sound System <> Construction

Sculptures The alien sculptures are made of urethane foam over a core of pvc or abs pipe, with various bits of hardware embedded. For the large PAliens, the heads were constructed in their own custom speaker boxes, with connections to the abs spine, and the subwoofer bellies were bolted to the spine before being foamed. The foam is either the spray-can foam or the two-part catalytic foam, which is mixed and then poured into plastic wrap loosely formed around their "skeletons." Two of the aliens have heads constructed by spraying urethane foam around an enclosed speaker, leaving a PVC joint exposed to connect the head.
	Sound System The amp that drives them is a 4 channel car stereo amplifier built into a pink suitcase and powered by a wheelchair battery. The suitcase has 1/4" jacks and a toggle switch built into it. The first two PAliens also had a small electronic circuit installed that "listened" to what it was saying, and flashed a blue LED light in time to the amplitude of the sounds.
Software The sound processing part of the system has evolved over time. In the first installation, two aliens were talking using a pair of loopers (a Boomerang, and a Line 6 delay modeler) and a reverb unit. The boomerang would play back audio that was sent to it backwards, up to two minutes later, and the line 6 looper would play what it heard in a continuous 19 second loop that built up layers of sound each time through.
	That system evolved over time using my Yellow Box performance system, which I also used to run my band Mixtape from Mars. It contained a full mixer, several loopers, vocal processors and reverb units, and was built into a circus-yellow box that fit on a cart. The whole system, including amplification, could be run on battery power (e.g. out in the desert), or plugged into the wall.
The next step was to move the sound processing into software. Using MAX/MSP, I built software modules that would emulate the various processors in the Yellow Box. Then I strung them together, hooking the modules up to independent inputs for the microphones, and the results of the processing to outputs to send to the amps. The system can drive up to 5 aliens, each on its own channel of processing, though it can be customized for more or fewer. The processing modules that are currently available are: looper, backwards looper, reverb, echo/delay, pitch shifting, continuously sweepable filter. To top it off, I incorporates the sound module from the Voice of Fire system, so that an alien could "choose" to store data from its microphone in a sound snippet database, and then play random snippets back later, though a series of processing modules.
	The most recent installation, October 8, 2004, at Mighty in San Francisco, used this setup, with 4 aliens running on software that looped, sampled, and processed the sounds from four mics hidden around the smoking section outside the space. Where to go from Here Given that the system now runs on software, there are two directions I would like to take the system. 1. Write sound processors that incorporate input from more than one sound source, combining the sounds by some kind of convolution, or letting characteristics of one sound source modify parameters in the other. 2. Audience interaction/control. I would like to place control units around the installation with knobs, buttons, or dials that modify the sound processing in some way, though what they do to the processing will not be labeled. The curious will find out anyways.