okay I'm a bit pissed now. actually i'm raging pissed! Wheeee!!! the nyquist/lindquist/someone-else-who-was-pissed sampling theorems are based on the possibility of mathematically extracting frequencies from digital information in a STEADY_STATE situation. That doesn't mean that a speaker will properly reproduce those frequencies. Consider the dynamics of energy transfer. A digital signal at near-1/2-sampling frequency will have two datum points. The transitiion between them will be dramatic! the possibilities of energy transfer will not be comparable to an analogue sinusoidal waveform. And that's why good analogue is better then good digital. Doug Self etc. did some work on ultra-fast analogue systems in the mid 90's, and designed some amps that were and are regarded as pretty good - but afaik he didn't get the theory right. YAAAAHHH!-- Peter Fairbrother