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
Be careful when it comes to power conditioning. Your problem may require a regeneration type conditioner that will stabilize its AC output. Most filtration conditioners have little ability to deal will voltage variances.

Voltage issues are extremely varied. Instead of listening to success stories on the internet I'd suggest using a manufactures trial period to determine if their product will affect your issues. After that you can still return the product and try to find a used version.
"Conditioner that will stabilize its AC output"

Which manufacture makes this type of product and/or recommend?
@ fishing716,I believe I would start with your power at hand!,high -end recepticals for each componet,a dedicated 10 gauge electrical line for each componet,with a dedicated ground for each componet with a 20 amp breaker for each componet, this is what I use,problems?,I have none!,the sound will improve dramatically as well!,this will take a few hundred dollars to do,the pay-off sounds in the thousands!Happy listening!