I just spent an hour playing around with 55 to 85 Hz test tones on my system. (I have 60 Hz chosen as the crossover for the fronts. Vandy 2 CE Signatures. The 5.1 analog crossover is 80 Hz.)

I have come to the following unfortunate conclusion:

If I set the phase correct between the mains and sub for the DVD input using the coax digital connection (the 2 channel analog connection responds the same way anyway), and then I switch to the 5.1 analog input, the phase is out.

(I'm using the Autosound 2000 discrete test tone CD disc.)

I have an adjustable phase knob on my sub. And an inverted input (180 deg out), so I can cover the entire 360 deg possible. I repeated this many times. I adjust the phase to get the maximum output on a Radio Shack meter using the coax or 2 channel analog connection with the phase knob. Then I switch to the 5.1 input. The max in this position is roughly opposite on the phase dial. Doesn't even matter if I invert the input. (One of the inputs is always higher than the other, the correct one, but even within the sound level values measured for each input, the max for the 5.1 input on the 950 is always NOT the same as for the coax/2 channel analog input.)

OK, just tried using an 80 Hz crossover, and same thing.

Digital vs analog crossovers can induce *different* amounts of phase shift in the signal. But I would have thought that this would have been anticipated and compensated for somehow.

Scott?


[This message has been edited by Kevin C Brown (edited September 29, 2002).]