Different sound between two channels

I have noticed recently that the sound of my left speaker is slightly different than my right speaker. The right channel appears to be brighter sounding than the left channel with the right channel sounding slightly richer sounding. I've tried reversing my speaker cables at the back of my Pass X250 and the problem kind of switches channels. I'm not sure if the problem is with my Hales T5's or the Pass X250. I think it may be a bit of both. I replaced the voice coils on both the tweeters of my Hales and the sound in general improved but the issue of the right channel being slightly brighter remains. The difference is noticable with the entire speaker as when I play just one channel or the other I notice this characteristic sound with the enire speaker. If my preamp is muted I will get a bit of residual noise from the amp in my right speaker(which is the brighter sounding speaker) and I imagine this residual noise is constant and may be causing the varient sound between the speakers. If anyone has any possible explanation or similar experience your feedback would be appreciated. I should mention that I spoke to Pass and they said it was normal for the X250 to be slightly different between it's two channels and that some residual noise in one of the channels is normal. I should also mention that what I'm experiencing is only noticable when listening right up to each speaker and is not noticable from my listening position.
A slightly different (or even more than slightly different) sound from each speaker is normal, in the sense that each speaker's immediate acoustic environment is distinctly unique, despite all the speakers being set up in the same room, due to their different positions within that room, and the fact that almost all rooms and furnishings are asymmetrically laid out to a greater or lesser degree.

But a different sound from each channel of a stereo amp being regarded as 'normal'? Shouldn't be. If the amp is working properly, each channel should sound indistinguishable from the other. To test if your electronics or speakers are actually playing are part in this, or whether it's just what I described above, you should also try swapping the speakers side for side and listen for what, if anything, sounds different.

If the only difference attributable to the electronics really boils down to the noise floor, and you can't hear this from the listening position, then don't worry about it. And remember, when you do any of the listening tests, make sure you're auditioning a monophonic program signal (and if you haven't been, all bets are off you my friend :-)
Thanks Zaikeman,
My room is symmetrical in that it is a dedicated audio/video room and it is 13' by 17' with only a couch in it. I do test with mono recordings and use the mono function of my Pass X1 otherwise. There may be anomolies when using the mono function of my pre as it doesn't send equal signal to both speakers but only blends the high frequencies. It's my suspicion that the differences I am hearing are due to the noise in the right channel which is even there if the preamp is off and is probably added noise to that channel when music is playing regardless of sound volume level. The differences I hear between channels varies with the music I may be listening to. It isn't noticable at the listening position but it bothers me none the less.
To obtain a true full-spectrum mono (summed) signal from stereo disks, you could also insert mated 2-female-to-1-male and 1-female-to-2-male Y-connectors in the line between source and preamp, or between preamp and amp. I still don't like the Pass explanation of different-sounding amp channels as being 'normal'.
Mitchb, are your speaker cables the same length for both channels?
I like your user name. Been there, done that. I'll be paying for my stereo for a long time.
Yes, my speaker cables are the same length. Aren't everyones? My speakers are exactly the same distance from the side and front wall, my system appearing to be symmetrical. I have a rectangular room dedicated for audio which is why I would expect the channels to sound the same. In my old place I had the same problem but attributed it to the room as the room was uneven and of course the WAF. In my room now I have room treatment throughout with foam on the side walls and cushions in all the corners. I am beginning to think that maybe the difference I hear when close up to each speaker is caused by the same residual noise I hear from the right channel when preamp is off and my ear is an inch from the tweeter. At that point I hear a slight hiss from the tweeter and a little hum from the midrange(right speaker) but on the left there is no sound. If I listen from my listening position to a mono recording I get a good central image. I only notice the difference if I stand right up to one speaker and then go right up to the other speaker. The right speaker is less "clean" sounding more bright and a little tinnyish. Almost as if there is distortion in that channel. Sorry for the long post but it's quiet at work.
Hmmm...so much for being something simple. Since the problem moves from one speaker to the other when you switch the cables, I seriously doubt it is the speakers. Unfortunately, it sounds like the problem is something internal to the electronics and could be as far up the chain as the source. At least it's not audible at your listening position. If it really bugs you, you could have the system looked at by a qualified tech, but you would probably have to take in the entire system minus speakers to get to the answer. If it doesn't bug you that much, I'd suggest to pour yourself another glass of (insert favorite beverage here) and enjoy the music. Good luck.
I eliminated the source and preamp by manipulating the interconnects from them and have concluded that it is the amp. Pass claims that the residual noise I am getting from the right channel is normal and I think that it is this noise within the channel that may be causing the difference in sonics between the tweeters. What do you think? It does sound good when listening to music and perhaps I'm being a little fussy but perhaps not. Shouldn't a $9000 amp sound equal on both channels when putting through identical signals regardless of where I'm listening from?
If you switch speaker cables and the problem switchs speakers then....it is not the speaker. If the problem doesnt switch then....it is the speaker(unlikely) or one of its cables. Try this first. Put everything back as before.

Then, remove the inputs from the amp, if the problem persists then....it is the amp. If it does not, replace the inputs on the amp and begin removing source inputs from your Preamp. One at a time, then power up and listen. Whenever the problem does stop the last piece disconnected and its cabling are the culprit. If you disconnect all the source inputs and the problem persists then...the culprit is the Preamp, to make sure, disconnect the inputs to the amp again.

A pain in the butt? You bet. But process of elimination is the most sure fire method. Good luck.
Carefully examine the placement of all your cables. It's possible that a single cable is picking up inteference from a nearby source.

Practically speaking you do not have a problem. From what you've written the noise is only apparent if you position your ear 1" away from the speaker. At that distance many if not a majority of systems will exhibit some noise.
Thank you all for your help. It turns out that after much experimentation this evening trying all combinations of cables being switched back and forth it turns out that two things could have been the culprit. One, I suspect a loose connection or something as when I switched all my cables around left to right and right to left, the problem mostly went away having a pretty balanced sound. What I did discover is that my CDP's right channel is slightly brighter than the left channel. I did not think this possible. Perhaps it's the mono function on my Pass X1 which only blends high frequencies and not lower mids or bass. I am getting a replacement player in about a week for other issues but at least it's not the Hales(no warranty) or the Pass X250.
In living with my system I notice the problem remains and is not a loose conection or the CDP. It is subtle but it is there. Could it be a room issue even though the room appears symmetrical? I do have windows on the right side of the room but they are covered with blankets. The windows will rattle with loud bass however. The bass has to be pretty loud.The right speaker generally all around sounds slightly thinner, even the bass which does not seem to go quite as low as the left speaker. But then again it's only noticable at the speakers and not the listening position. My concern is that it's a speaker crossover problem and since Hales is out of business I wouldn't know where to begin to get the crossovers fixed or even looked at.
Please help. Thanks
I figured out that I had a crossover problem with one of my speakers and am now in the process of having both crossovers redone with high end caps, coils and resistors. The crossovers of my speakers were checked by a technician and one was OK but the other was off by over 10%. The problem was in fact with the speakers. As well I noticed that the right and left channels of my Pass X250 sounded quite different so my amp is now at Pass to be looked at and adjusted or fixed where necessary. I miss my system as it is now out for repair but I'm sure I'll get a better sounding system when the amp and speakers are returned. At least I won't be haunted as to whether or not there is a problem with speakers or amp. Problems solved.
I must add that my amp returned from Pass Labs sounding better than ever with both channels sounding the same as far as I can tell with the little Jamo speakers I'm using in place of my Hales.I can only imagine what the Hales will sound like with the upgrade/mod/repair done to them.