Sherlock Holmes needs clues

Rives: What your are describing sounds like trying to measure the impulse response of the room.

1. What would you use as a noise burst source?
2. What would be your detector? I assume you would locate the detector at the listening position. [I can do an FFT in MATLAB, but need to get the time series data input to my computer to do the plots you describe]
3. What characteristic behavior would you be looking for in the waterfall plot? A more rapid decay of energy in this band?
4. What calculations would you make? Anything besides the peaks and nulls of standing waves? I have an irregular shaped room , but do have a program I use for SONAR development that would give me the normal mode structure for a room like this.

Thanks for the input. I would like to give this a go, as long as I have access to the tools I need to make the measurements.

Judith

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.

Ivanj, the speakers/amp are the very same mentioned in my orchestral brass question. I believe they are suspect here as well. A move to new speakers/amp is in my future. However, I want to be certain that I am actually treating the correct disease.

Plato, Relevant crossover is at 3 KHz. Your idea is the very first one I checked out.

I put a heavy quilt over my head and one speaker, listened to very near field direct path. Problem is audible. So I am thinking the room is not my problem.

I am going to do some equipment swapping tomorrow.

Some interesting ideas provided here. Thanks.

Marakenetz, What does amplifier clipping sound like. I know what it looks like on paper, but don't know what it sounds like. Shouldn't clipping artifacts go away at reduced volume levels?

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.

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

Subaruguru, glad you spoke up here since I know you have the same CDP I do.

The Nautilus 805s have a 6.5 inch Kevlar mid-range driver. Note that the phenomenon I am referring to occurred on the Magnepan 3.6 as well, in a totally different room driven by different electronics.

I moved my speakers around quite a bit to no avail.

I do not mean to spend people out on this problem, but I do appreciate the interest.