<snip> > > There is a school of thought that says that the fact that the inversion > > of a > > some steady state non-symmetric signals being audibly different (which > > > > appears to be the most common proof of absolute phase being important) > > is > > proof that loudspeakers are not quite as linear and symetrical as they > > should > > be so maybe with a "perfect system" it would be a different story? (I > > jest > > slightly) > > Sure. However, we only have loudspeakers, and if they sound better with > correct polarity, then that is what we should use!
I would be interested to know whether or not the results of people's polarity decisions based on listening match with other people's conclusions. I wonder whether or not there would be a difference of opinion with different speaker technologies (ie do electrostatic panel speakers behave the same way "upside down" as conventional cones? my gut reaction is not - they won't necessarily be correct but they will almost definitely be different). <snip> > > I would be amazed if any multi-microphone recording (even so-called > > time-aligned multi-mic classical recordings) came anywhere close enough > > to be > > phase coherent in themselves so any improvement would be due to chance > > > > psycho-accoustic affects rather than any "absolute correctness". > > I'm not so sure. If each channel of a multi-mic recording is in correct > phase, then the result is simply a superpositioning of these channels. > Sure, individual distances (time and volume), and low level ambient > information shared between the channels would be a bit of a mish-mash, > but the fact would remain that the leading edge of transients from all > channels (from the instruments dominating each channel) would be in the > correct direction. I've spent quite a lot of time in the past being paid by people to mic up and amplify / record concerts and while you are correct that the phase information for each microphone would indeed be correct, the absolute butchering of the soundstage and any background reverberation when using multiple microphones. Of course, this is quite often preferrable to the problems of working with a stereo pair in terms of balance and gain (especially in a live situation) so often it is the only way to go, but in terms of discussing a recording being really "correct", I think that this only really applies to single point stereo pair recordings. > Alex Twisleton-Wykeham-Fiennes Wrote: > > > It is true that you system has to be pretty good to hear the > > > difference. I had difficulty hearing it before i got the TacT RCS. I > > > imagine headphones would do the job at a lower cost, however. > > > > Just out of interest - are you switching your phase before you go into > > the > > TacT or after (ie on the room corrected signal)? Do you have an option > > on > > this? I would be very interested to know if there is a difference on > > your > > system. I could imagine that the room specific processing that the > > TacT > > performs on the digital signal would be much more sensitive to absolute > > phase > > than the signal from the source that is being fed into the processor. > > > > Alex > > That is an interesting point. However, if you regard the TacT pre, the > poweramp, and the speakers as a "black box" (let's say, a digitally > corrected active loudspeaker), then this question would be pointless. > If the corrected system gives much better performance with a input > signal of the correct polarity, then that is what we should use! > > I do understand your point though. Is the digital room correction doing > something that exagerates polarity differences, more than a perfect > phase coherent speaker in an ideal listening room would have done? I > don't know. I do know that people with very good systems, but no > digital room correction, report the same type of audible differences > between listening to correct or incorrect polarity. (I should say that > "correct" here means, best sounding! I have yet to verify that the best > sound corresponds to any recording's correct absolute polarity. > Something that would be an interesting project! Correlating phase-data > for various CDs with other audiophiles might be a good start.) > > Also, I do not know if the polarity inversion of the TacT is done > before or after the digital room correction processing. The key point here is that if the polarity is post TacT processing then adding the functionality to the Squeezebox will probably not have the same effect. However, it should be a quite easy effect to implement (although a little bit of thought would need to be performed as to whether or not it is a global switch for the output stage or a per-track decoding option, especially with cross-feeds) and it would be an interesting thing to play around with. Alex _______________________________________________ Discuss mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/discuss
