Sherlock Holmes needs clues


I have determined by listening to many different solo piano CDs that something unpleasant is happening consistently across all CDs whenever the piano plays in the octave between about 500-1000Hz. The beautiful warm, natural piano sound becomes somewhat thin and tinny, as though the piano needs to be voiced. Both above and below this octave, the piano sounds warm and natural. I would like to isolate the component (or resonance, or room interaction) at fault.

I plan to play Sherlock Holmes a bit - but would appreciate any thoughts people might have to assist with my learning curve.
judit
Frankly, if the phase angle and impedence is brutal at the frequencies you are mentioning the amp would actually only be putting out a fraction of its "FTC" output. An example would be a 200 wpc SS amp - into 8 ohms - which actually is only putting out 6 watts or so at this nexus. Thus clipping occurs even though the volume is low. (This is why, in part, so many of the 70s SS amps of high power did not drive real speakers as well as a 35 watt Dynaco tube amp.) Am I being clear?
Sherlock Holmes has spotted Dr. Moriarty ... Today I took 7 piano CDs to an audio store and listened to an entirely different system than my own - Magnepan 3.6, Levinson CDP and pre, and Audio Research tube amps.

I must tell you how surprised I was to find that this system had exactly the same problem with piano that I was hearing in my own listening room. This has convinced me that Plato may have hit the nail on the head. Digital playback is where Dr. Moriarty hides. Either there or in my ears.

The problem with brass playback I am having, appears to be unrelated, as it did not occur during today's listening session.
Hmm...lots of midrange drivers (esp 5") have a rising frequency response between 300 and 1k or so, which will thin out a piano,sometimes with a "cuppiness" coloration on human voice, too. For that reason I've preferred 6.5" midranges as a rule for inexpensive speakers. I've designed both 5" and 6.5" two-ways, and have a Steinway B in my room as a reference, and could NEVER get the 5" to sound as neutral as the 6.5. (Yet a GREAT 5" CAN be made to sound neutral, of course, as was accomplished Verity Audio in their Parsifal Encores, for example). Also note that room reflections around 800-1k are VERY position sensitive. Try moving your listening position just a few inches to see if the mids even out. That may tell you to play around with sidewall-damping schemes like sofas/pillows (what I use), etc. I do NOT buy the CDP suggestion as the source. There are other issues ("digititis", etc.) with CDPs, but a rising frequency response in the midrange isn't one of them!
Good luck.
Judit-
Could you please list the CDs that show this phenomenon? I'd like to try it on my system and report back. Perhaps you could describe where, timewise/trackwise, the phenomenon occurs?
Thanks,
IJ
IJ,
Several recordings which are pretty common members of people's libraries are

Nojima Plays Liszt, 1987 Reference Recordings
If you have this try track 2 La Campanella. I identified two spots where I think this is pretty pronounced; from 45-55 secs then from 1:30-1:45 seconds. However, the problem is sprinkled throughout this track.

Even more common in everyone's library is Patricia Barber NightClub, Track 1, bye-bye blackbird, during the long stretch of piano solo - listen to the segment from 2:35-2:48.

Another example: the Earwitness Transcriptions distributed by Madrigal Labs. Steinway Reproducing Piano. Disc one, track one Padereski plays Paderewski: Caprice Op.14 No.3 in G. Listen to the piano trills between 12-14 secs. The trills above and below these in frequency a bit further on are all clean and natural. However the trills between 12-14 seconds make my teeth resonate.

All three of these discs presented the same unpleasantness on the two entirely different systems that I listened to. Perhaps the one thread that tied these two systems together is that they retail for about the same amount of money.

Judith