Sorry, forgot to ask a couple of things. Will Jack or other similar APIs allow passing of DC signal? If so, do we have to worry about speakers blowing up or do soundcards protect against DC?
If not, can anyone tell me what the most CPU efficient way of modulating/demodulating a control signal might be? It occured to me that one could just use a very high frequency signal and have amplitude represent the DC control signal, requiring the receiver to use some sort of RMS amplitude tracking. This could also allow more than one control signal to be passed in one audio stream if we had several composite sines that were filtered apart again on the receiving end if the CPU demand of the filtering was less important than saving audio channels. Any thoughts, feedback, or redirection appreciated. Iain
