sgreg, I think that is an idiosyncrasy of your system.
Teo_audio, what in the world are you talking about?
rvpiano, I have an set of Cesar Franck's complete organ works. There are several pieces with an A0. That is 27.5 Hz. Your vision actually blurs forget about everything in the house shaking.
Audiophiles shunned loudness compensation in the late 70's. It was felt that any analog filtering caused more harm than good which I personally believe is true. We simply played the music at the right volume. But, now we have digital filtering which is a whole different ballgame. Once you are in numbers you can do anything you want including programming loudness compensation to match the any volume. This allows you to play a piece at lower volumes with the right balance. Unfortunately, very few processors offer dynamic loudness compensation. You have to program you own curves and select them manually.