Thanks Gonk. It seems I did that at the beginning, because it is exactly at 0 dB for 75 dB SPL. Still I find most listening is done at master volume settings between -20 dB and -10 dB. -10 is quite loud, much louder that the 990's manual calibration tones. It is not live concert loud, but loud enough. It is hard to imagine listening to music or a movie with the volume set at 0 dB for any length of time, but then I still hear enough high frequency content that I care about it after all these years. :-)