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
Nah,I'm a professional musican and know what I'm saying.
Besides significant other hears the same thing as myself

Could it be that the bass is tightening up as the amp(s) warm up and stabilize? Is it going from bloated to more lean with better definition?

Chuck
Could it be that you are not hearing less bass just tighter bass as your entire system warms up ?
I prefer to let my system play for about an hour before I do any serious listening. It could be your room or placement of your speakers. Not your amp.
Just a thought.

Most likely your system is on the edge of lean and when it warms up it goes over the edge. Make adjustments in speaker placement and things that make a difference in tonal balance like selecting cables after the system is fully warmed up.