Loss of bass & full spectrum sound


Can anyone shed light on my audio system problem?
I have PSB Synchrony one,Musical Fidelity M6i + cd player & turntable along w/video
The sound is Full with deep bass then after an hour it reverts to a different unenjoyable presentation with no life..
This has been going on in my NYC apt for about a year
I have a great sound then it changes (white-washed).
I adjust speaker cables(AQ biwire comet)& occasionally it regains a full body sound however after about one hour it's gone.
All my components have been checked to function properly.
I suspect an electrical problem but voltage is steady 120
Any similar experiences?
fishing716
I've tried one positive & negative solution using binding posts that came with speakers.
It didn't work,sound was even less appealing
Karma not withstanding!
Been told I've now entered the "twilight zone" & I need an exorcist.
Actually I've tried everything imaginable but the problem persists.
When I've lost the dynamic & good sound-
I notice the lower notes are still playing but the impact & "growl" has completely left
I tried jumper cables instead of biwire but the problem persists.
Audioquest Comet biwire 6ft cables w/banana's are not defective
Are you sure it's not you instead of the equipment? Has anyone else noticed the same thing listening to your system?

Can you borrow a different amp to try?
How do you know that the cable is not defective?How do you know the binding posts on your amp are not defective? I would try some inexpensive speaker wire like zip cord in place of the Audioquest and see how that works. You will solve this problem it just takes one step at a time.