I would appreciate some suggestions for implementing a stand-alone audio mixer/equalizer box using commodity components, in the shortest development time at the least possible cost. I am tending to want to to use four PCI sound cards in an older PIII 1u rackmount cpu to create a four audio bus/eight inputs mixer, with four independent equalizer channels. It should be controllable using an arbitrary protocol over RS232 or ethernet, not require a resident GUI, nor local mass storage except perhaps flash for program loading, and won't do any local capture, only audio I/O at 44.1 or48kHz sampling rate to and from unbalanced line level connections.
Some preliminary thoughts are to use a version of *IX as the o/s and layer ALSA and LADSPA with plugins on it, connected with the 'jack' framework, and for testing just control it through remote shell command scripts until a complete control program is written. Since I'm using low-end hardware, I had dismissed using 'Pulseaudio' as a framework (unless convinced otherwise).
Should I be considering some other o/s or RTOS?
Has this been done as an opensource or freeware project (I don't find much on the 'net)?
Replies are much appreciated.