Sherlock Holmes needs clues

Elementary, my dear:

It could be your CD player -- piano is an instrument with many complex overtones. Many CD players (even expensive ones with favorable reviews) fail at trying to reproduce natural sounding piano music. violins, cellos, and even brass instruments are difficult for CD to get right. That's why many folks like analogue!

Plato, Hate the thought, but hear the message loud and clear. As it happens, my CDP is an "even expensive ones with favorable review" player. Thanks.

Judth: We use the ETF software a calibrated microphone and pre-amp from Germany, and couple all of it through a PC computer. This provides the noise burst. The detector is at the listening position, but we generally vary it with about 6 sequential measurements to get some averaging (but do not actually use an averagin function as it can be misleading) It's pretty amazing the measurements we can achieve today with about 1/10 the cost of hardware required only 5 years ago. You can go to our website at see the software and measurement tools we use:
http://www.rivesaudio.com/software.html
The kits we sell here are primarily for our dealers that take measurements for us, but do still provide them to end users that feel they need this level of measurement for themselves.
The calculations are pretty basic if you are into room acoustics. Look at the impulse response and determine if it is being affected by the room and how much. If the impulse times match the distances for reflections, then it coincides with the room, if not, then you need to look elsewhere. The real issue becomes is there something different going on with the time energy curves (this can be viewed in the waterfall plots as well) in the frequency you are describing as a problem, vs the rest of the frequency spectrum. As Sherlock Holmes--I would look for these differences--in all areas of measurement (not just the ETC and waterfall) and then try to logically deduce why they exist and how they might effect the overall performance. I do agree with you--it is a Sherlock Holmes exercise, because you have to go after what you first suspect--it may lead you to nothing, in which case you have to look elsewhere--thus I have not provided a solution--just some areas to look into further.

Yeah, Judith -- I think you may need to test the analog waters. One pretty simple way you can rule out room interactions is to listen to the music via a decent pair of headphones. Heck, even a cheap pair of Grado SR 60's will tell you what you want to know. If the piano still sounds a bit odd through competent headphones, then you will know it's your source (especially if you use the CD player's headphone jack, if one is present).

Of the three sources I use for reference, I'd have to say my least expensive source (Teac X-700R reel to reel recorder) sounds the most natural and true to the music. This would be followed closely by my Michell turntable and my CD playback system in that order. The old reel to reel exhibits the most background noise (sans its noise reduction) but the timbre and harmonic structure is exceedingly true-to-life. The CD playback gear is dead quiet and very dynamic, yet compared to good analog, the authenticity of the various instruments is not quite "there". But it sounds close enough if one only listens to CDs, without a direct comparison to credible analog... Actually my digital gear does piano quite well since the latest DAC mods and the performance gap between my three sources is surprisingly narrow (yet clearcut). Also, the more resolution your system has, the more apparent/glaring any imperfections will be.

Platos suggestion is a good one for testing the CD player. Whatever you do find, please do post it here--now I'm curious.