Bass leaves after amp warms up?


I don't understand-after my Musical Fidelity M6i amp warms up for about an hour I notice the deep bass & kick drum aren't the same.
They sound less musical with loss of weight/depth.The notes are there but the moving of air have left.Sound is has much less impact and boreing.
I had the same problem with Bryston amp so there is no defect with amps nor with the rest of my equipment/
PSB Synchrony one speakers,AQ cables,Bryston CD Player.
My question has anyone heard similar & is there a plausable reason?
fishing716

Showing 2 responses by ojgalli

One more possibility: dynamic compression from overheated woofer voice coils.
It's your ears, not the equipment. If you were to take a measurement, I'd bet you there'd be no change.

I frequently find, within the first 5-10 minutes, that I increase the volume about 3 dB. That's at an average level between 80-85 dB. It's a bit like your eyes; they adjust to brightness—your ears to sound pressure.