bwaslo

Chris, Impressive setup, wish I could hear something like that someday (not sure I have room for a pair of 402s in my small room, though). One technical quibble, of probably little importance, though: the phase graph you show in the first post of this long thread: Is not really showing a linear phase. The frequency scale of that plot is log, not linear, so a straight line that is other than 0 or 180 degrees doesn't mean the phase is linear. Linear phase (waveform faithful) would require a straight line for of the phase when the frequency scale is constant in units of Hz (not in octaves, as the slope with a log-frequency plot would show). Delay (seconds) would be proportional to the negative of that slope -- linear phase implies constant delay. Here is a (rough) plot of what your data might look like in a linear-frequency graph: As shown, the delay (i.e., downward slope) below about 2kHz is much larger than it is above 2kHz. Here is the same linear-frequency plot with the usual phase wrapping (to get the vertical down to a more visible scale): The phase response is quite linear from 2kHz to about 12k and likely minimum phase above that (phase dropping due to magnitude rolloff). Typical rule of thumb for "reproducing square waves" to the eye is that the phase be linear and magnitude need to be flat from 1/10x to 10x the square wave frequency (and the phase must also flatten near 0 degrees when delay is compensated to achieve a horizontal line). I won't say that this is actually very important, though, just being technically picky. I went to a fair bit of trouble to get my Synergyish speakers to be relatively linear phase in the crossover -- and then added a FIR equalizer to smooth the phase further-- but the difference didn't cause a golden glow with angels appearing in the room or anything. I'm pretty sure (but, from an uncontrolled test) that there's a positive difference in the midbass sound on transients when phase was linearized, but it's still not something I'd bet much money on. At the high frequencies, magnitude fixes are definitely audible, but phase differences (comparing to a system with an impulse response that was already pretty compact) didn't seem to make much difference to me. Possibly if the HF phase had been initially really screwed up then HF phase linearization might have been audible. Bill