[Peter Wieck[_2_]]

I think you are missing the point. If too much energy is being dissipated by the speakers in the high range, then too much energy is being dissipated in the high range. And, the brute fact of the matter is that there is not a whole lot going on above 15 kHz anyway. So if the OP perceives that his speakers are overly bright, we should start there.

I agree that attenuating the high range is not the answer. But neither is tweaking room acoustics. We need to work with the Human Ear and how we perceive sound at various volumes.

Which is why balancing the speaker output does seem to be an answer, especially given that one does not normally blast music in an office. At low volumes, in general, not enough energy gets to the bass driver(s) to balance the treble, especially as speaker efficiency drops. These are 88 dB speakers, not horrible, but not great either.

Eschew needless complexity. If the electronics have a "Loudness" function, start there. If they have tone-controls try *BOOSTING* the bass - again that nasty issue of low-volume weak bass is more at-issue than excess treble (at low volume). Failing both these things, is it possible to relocate the speakers, moving them more towards room corners, or closer to the floor, or similar so as to help 'boost' the bass response. However, this might sacrifice sound-stage.

Only after the obvious fixes have failed should we push towards more heroic measures.