Amp Specs esp. DampFactor : Citation, Adcom, etc.

"Aewhistory, you might be surprised to find out that research about the way the ear hears and how the audio system interacts with that, has really not been dealt with all that much in a way that is not classified. "

That's disappointing to hear, although perhaps not surprising (and I shouldn't have presumed). With all the progress that the sciences have made, there is so much more to do; a fact made clear by our progress. If anything, our advances have really made it apparent how much of what we thought we knew we, in fact, do not know or have incomplete, need to rethink, etc.

However, thanks for sharing that snippet about something that has been done. Although this thread has gone completely in a different direction than I'd intended, I'm really quite happy with the discussion. I just wish I had something more to add, but I have been reading along consistently.

One last question/point: is there anything one might call research dealing with the linkage of critical listening and planar/electrostatic speakers? I might be totally off-base, but I remember hearing once that more than half of Stereophile readers had some sort of planar/eletrostatic speaker even though there are FAR more box-speaker manufacturers. I have little doubt that this is not representative of music listening in general; it must be representative of audiophiles and/or critical music listeners, right? Anyway, just wondering.

Atmasphere,

As I understand it, our brain works more in time domain than frequency domain. We cannot hear above 20kHz but recent research shows that people can still tell the difference between 20kHz and 50kHz bandwidth listening to music. All spacial clues are also defined by transients.

A lot of this information is lost or changed in digital processing. On one hand it is almost impossible to recover 20kHz sinewave when whole period is defined by two points of 44.1kHz (AFAIK Nyquist criteria protects only frequency information) on the other digital filtering alters step response making ringing to appear after (as it should be)and BEFORE pulse itself. Our hearing is sensitive to the shape of the wavefront. Newest filtering schemes (non-apodizing filters) used, for example, in Meridian CDP have (Stereophile review) normal looking step response and better, more natural sound.

Kijanki, would this explain why some have argued that keeping the signal above 20kHz is still necessary even though it isn't audible in the 'traditional' sense? Or is that what you're saying and I'm just repeating it? :-)

Thanks, Aaron

Aewhistory, I had impression that keeping bandwidth well above 20kHz prevents phase shifts within 20kHz but as research suggest it might as well improve transients that our brain processes.

Technical spects have no value to me. I'm not even sure what they mean. Is low THD amp better sounding than high THD amp? Same goes for DF.

To me, at least theoretically, a low THD should represent a cleaner signal path. Of course, this is theoretical, but what that spec. means to me is that the amplifier is not introducing outright distortion into the line. Of course, having said that, what constitutes distortion needs some definition.

This may seem completely unrelated, but in my field, history, the same types of arguments are made over trying to define terminology, categorizing, measuring, etc. And the results are no less frustrating. So while I can't claim to understand the finer aspects of EE, I do understand the academic aspects of the debate and appreciate them, despite my somewhat simplistic approach.