here is my delima............

I have a cj - 2500a, cj - pv 12, alon 4's,rotel 975. i have tube rolled my brains out, settling for amperex nos. I use tara labs vector 2's between the power and pre, ive tried different ic from audio art, to morrow, to audioquest for the other components, one makes the sound to thin, one makes the bass to boomy, I cant seem to get it just right. i use axiom tri wired speaker cable. the problem is i have this mid range, mid bass vacuum that i cant seem to get rid of. i wonder if my system is starting to degrade, after all it is an older system. or is this a product of lets say the speaker or amp/pre manufacture design. i did read some where that the older alons had a problem with the midrange on some of their speakers. just about every thing i could think of to remedy this problem but all i get is back to square one. i did recently have my local power compy come out and was told my box was only 100 amps. i did some calling around on that and was told my house could be under powered, which is just as bad. i have noticed that when i am playing my system and the heater comes on, the sound degrades. and i do notice the fluctuation like others in bad areas in sound from lets say 11:00 to midnight maybe(peak time) this hole in my midrange is not always there, it varies from day to day and time. i do notice that as i turn up the volume i tends to get worse. ive tried replacing all the drivers in my alons, but that lasted for just a while and then the problem came back. also when i turn up the volume, i get very little gain past say 11:00, after that the sound quality gets terrible. any help at all would be very much appreciated..............