Shawn,

I'll have to check the info that came with my SPL to see what the slow response setting actually does (e.g. RMS or average) versus the fast response setting. Regardless, I used the slow response setting for calibration and when I played the cds in stereo, so I'm not sure the fast/slow setting is a reason for the difference.

My sample of cds was pretty small when I made the measurements I noted above, but I don't recall their being a real significant difference in volume between cds. Yes, there is some variability (in particular one George Winston cd stands out as louder than others in my collection) in how loud cds sound.

I agree that if all the speaker volumes were increased 1db it would be hard to tell, but as I think you noted, when only one is changed it stands out. My second question was, or should have been, what volume change is noticable when only one speaker is adjusted? I notice the difference (e.g the "location" of the singer drum, specific instrument location) when a 1db (as noted on the setup screen) change is made to the left or right channel in stereo even when the master volume is at -30. Or another way:, When I make a 1db change on the setup screen do I really get a 1db change assuming -30 master volume that equates to 80 to 85db at my listening position? Sorry for the number of variables.