Bass leaves after amp warms up?

04-22-13: Atmasphere
Al, 0.7 db across a spectrum can be quite noticeable to the ear, whereas on a sine wave is undetectable.

Thanks, Ralph. FWIW, though, note that the 0.7 db was between maximum instantaneous values, which might have occurred on as little as one sample out of the many millions of samples in the track. Averaged on an rms basis across the entire track, the difference was 0.4 db (comparing the sub-300 Hz content of the "good-3db" and "bad" waveforms).

You might normalize the two tracks, invert the phase of one and play them simultaneously, then you could hear the 'missing' bass.

Actually, prior to posting my report I spent a good deal of time trying to do exactly that. Inverting one 2-channel signal and summing it together with the other 2-channel signal whose volume had (at least approximately) been equalized. And alternatively, playing them both at the same time. Unfortunately, I couldn't get the software to accomplish that properly, after trying several alternative approaches using two different software programs. Not sure why.

Also, "normalizing" is somewhat ambiguous in this case, because the differences between the "good" and "bad" waveforms are different depending on whether peak or rms values are considered.

Best regards,
-- Al

HI AL

What is the goal of what what you are discussing?
(which I don't understand)
Can I ask when you listen to both versions if one sounds more satisfying than the other?

What is the goal of what what you are discussing?

The goal is to characterize the symptoms as precisely as possible, in technical terms. Hopefully that would help to identify or at least narrow down the possible cause(s).

Can I ask when you listen to both versions if one sounds more satisfying than the other?

Hard to say. Partly because neither sounded satisfying, due to the excessively hot treble, and to some extent also due to a general lack of transparency. I have no way of knowing, of course, the extent to which all of that may have been contributed to by the original recording, vs. your system's reproduction of it, vs. your recorder and microphone.

Also, as I indicated, precise equalization of volume levels was problematical, which further increases the difficulty of making any judgments.

Can you provide an answer to my question about whether or not your recorder applied AGC and/or peak limiting when your recordings were created? If you are not sure, let us know the make and model of the recorder. If an external microphone was used with it, let us know its make and model as well.

Regards,
-- Al

I use Marantz Professional cd recorder CDR400 w/built in mic.

AL I petitioned my dealer to lend me a dedicated 250 w amp from Musical Fidelity.
Do you feel this will resolve the problem?