...they sucked the life out of the sound... the high frequencies in that reverberant field are more likely to be missed...
That makes perfect sense.
I used to think that classical music (more higher frequencies) sounded great on my speakers.
But then just the other day, I listened to some classical music (w/ the acoustic panels), and it did not sound great at all.
And then last night, I officially removed the 4 panels, and the classical music really sounded great again. It was not a double-blinded study, so I can only say it was a subjective observation. But it makes more sense now.
Those panels were sucking the life out of my speakers!!!
Thanks to you guys, I will never waste another dime on acoustic panels again!