Quote:
Originally Posted by WiWavelength 
Conversely, large scale orchestral recordings (or anything recorded w/ spaced omni mics in a large venue) can most certainly contain phase differences between channels. For example, if the timpani is 40 ft from the L omni and 50 ft from the R omni, then bass from the timpani will arrive at both mics approximately equal in level but 9 ms later at the R omni. As 55 Hz has a wavelength of 20 ft, that 10 ft or 9 ms difference between the mics means that 55 Hz sound from the timpani will arrive at the L omni in phase and at the R omni 180° out of phase (i.e. one half wavelength later). That bass does not cancel in the hall. It does not cancel on the recording. But it does cancel in playback if bass management electrically sums all channel bass frequencies below the crossover point. Separate L/R bass management, however, can at least partially preserve that phase difference in the listening room.
AJ
Conversely, large scale orchestral recordings (or anything recorded w/ spaced omni mics in a large venue) can most certainly contain phase differences between channels. For example, if the timpani is 40 ft from the L omni and 50 ft from the R omni, then bass from the timpani will arrive at both mics approximately equal in level but 9 ms later at the R omni. As 55 Hz has a wavelength of 20 ft, that 10 ft or 9 ms difference between the mics means that 55 Hz sound from the timpani will arrive at the L omni in phase and at the R omni 180° out of phase (i.e. one half wavelength later). That bass does not cancel in the hall. It does not cancel on the recording. But it does cancel in playback if bass management electrically sums all channel bass frequencies below the crossover point. Separate L/R bass management, however, can at least partially preserve that phase difference in the listening room.
AJ
Your example above would have merit if that scenario had any thing to do with reality. First of all, in your example, the sounds would be arriving 10ms apart and would not result in pure cancellation. More importantly, in reality, the mics will be receiving multiple impacts as the sound waves reflect off room surfaces over the span of hundreds or thousands of ms. Furthermore, stereo subs are pointless as the wavelengths are so long that we cannot determine directionality in their operating range. And finally, if you want to run stereo subs with Audyssey it is easy enough to run the fronts as Large with their own subs and then run a third sub for LFE only. You don't need stereo sub pre-outs to do that.
Last time I checked, this was the official product thread, not a debate thread. If you think the Onkyo is better, why are you still here? Go buy an Onkyo and move on.
