Another thing that will cause that is an unsemetrical room or a room with an opening on the side to another room. I cant give you the technical reasons but I have found trying to make this adjustment through the balance controls just doesnt sound as good as speaker adjustment. Yes it is much easier but the speakers just dont seem to blend right or as well.
Brian have you swapped around your source component interconnects so as to reverese Left & Right channels at various points along the signal path? You might have a marginal connection or cable, or even a component that's not within balance.
Hi Bob, I have noticed this for years in my system with numerous componants and they have been hooked and unhooked, I am sure it's the furniture that causes this.
I struggled with this for many months. It's bad enough that so many mastering engineers either seem to have worse hearing in one ear or a bad channel in their system, but to have to live with a non-symetrical listening environment is the pits. It sounds like you haven't tried acoustical treatments, which I highly recommend - check out some of the other threads. I believe that the balance control is frowned on if it adds an additional component to the signal path when it is off center. If this isn't the case, by all means use it (if the treatments don't work 100 percent). My purist preamp doesn't even have a balance control, so in the end, I actually replaced the gain resisters to get that last bit of shift.
I would suggest that you measure the speaker and room response of each channel independently. See if there are certain frequencies that are being attenuated by the room in one channel more so than the other. As previously mentioned an opening or other asymetrical occurance in the room can throw off the balance. Once you find what the frequencies are being affected you can make some modifications in terms of accoustical treatments to the other side to balance things out. If you are lucky, the frequencies affected are on the high side (say 1k and up), and then some absorbing material (sonex, RPG, or ownes corning panels) may be all you need. If the problem is lower, it's still a solvable problem, but likely more complex.
My system slightly favors the right. After alot of experimenting, I realized that the reasons are that my hearing is not as good in my left ear and that I have drapes on the left wall and not the right. (My slight hearing loss is primarily in the midrange area. This is due to years of loud car stereos.)
The system imbalance was most noticeable for me when the vocal did not sound like it was directly in the center. Trying to adjust the system with the balance control can make the vocal sound like its coming from the center but it throws everything else off to the left because the hearing loss and room anomalies are not the same at all frequencies. Therefore, adjusting the balance was not a good option. Two main reasons: 1) alot of low bass loss , and 2) loss of low level detail in the right channel. I did find that I could minimize this problem by getting the speakers optimally placed in the room. However, I always take great care to keep each speaker the same distance from my head and I use a laser to make sure both speakers are toed in at the same angle. In other words, my recommendation is not to move one speaker but to find the perfect place for the pair. Experiment alot by changing the distance between the speakers, distance of speakers from the rear wall and side walls, etc. Also, room treatments and room rearrangements can be helpful. and i babble on...........
I had a very similar situation only my system favored the right side. This occurred whether I switched cables, components, or even swapped the L/R speakers. Someone on A'gon suggested I check the output of each speaker as sometimes manufacturing variances can produce slight differences. With this in mind I ran a channel balance check with my pre/pro and sure enough the right speaker was about 2dB louder than the left. Once I corrected for this with the pre/pro everything snapped into focus. I have no explanation why the right was still favored when I swapped L/R speakers--it makes no sense but neither does losing one sock every time I do my laundry--some things we may never understand.
I since have been using stereo preamps instead of the pre/pro for serious listening and have found the balance control to be an extremely valuable tool. Not only because it allows me to correct for the above, but also because I realized that many recordings are very different in how they are balanced, and while the singer may be in the center for one recording they may be off to the left or right in another. I've become addicted to being able to center these recordings rather than contorting my neck/head to suit each recording engineer. These are not huge adjustments so I don't find they dramatically impact the balance of the rest of the recording, and I find I enjoy listening to music more with the balance "optimized" for each recording(and even moreso when the balance control can be adjusted using the remote--very helpful).
Sorry for digressing, but it seemed related. Best of luck.
Oh, one more thing. I for one would not vary the distance of the speakers to adjust the channel balance. My guess is although you may achieve better balance you probably introduce several other negatives to the sonic picture by doing this. This is just a gut thing and I have no scientific or engineering rationale to back it up, so take it for what it's worth. Personally I'd much rather fix the problem with room treatments or a balance control. Again, best of luck.
If room treatments won't solve the problem (or are impractical from an aesthetic standpoint), then it seems like the balance adjustment is your best bet.
I would NOT adjust the speaker placement in such a fashion that the speakers are unequal distances from your ears. This will introduce problems with arrival times that could be more un-nerving than a balance shift.
Finally, another trick you might experiment with is to adjust the toe-in on the right speaker. There was a speaker placement guide that I read (I think it was from Audio Physic - but it dealt with Psychoacoustics as a factor for speaker placement)...anyhow...it recommended adjusting toe-in on each speaker separately until you reach the optimal balance between soundstage and imaging. It also said that it would be normal to have one speaker toed-in more than the other.
In my room, I measure the distance from each speaker to the exact center of the listening position to within about 1/8", and then fine-tune the exact distance by ear. That helps, as there's an optical illusion in my room that makes the right speaker look closer than it is.
In a previous room, I was getting the image pulled to one side despite all my careful measuring and wall treatments. By chance I found that a vertical cabinet edge well off to that side was the culprit. Sound was diffracting off the corner, which was acting as a secondary sound source. I would hang a little damping material on the cabinet when I listened, and the imaging was vastly improved (especially on close-miked vocals. I can't stand it when the sibilants come from a different point in space from the rest of the voice). You might have someting similar going on in your room - you might try draping a thick towel over various pieces of furniture to see if you can find the culprit.
Well assuming that doesn't help, I would suggest you use the balance control rather than positioning one speaker farther than the other, because you want to preserve the timing cues that would otherwise be skewed if you moved on speaker farther away.
I have moved the speaker to compensate for this and it works quite good. You only have to move it an inch or two so the side effects are small and better then an off center image. (at least to me) Ill also save you a ton of time and tell you that if the image in more on the right you adjust the left speaker and vice versa.
The alternative to a balance nob is a volume nob for each channel-slight mod.
I think the question was why one method is prefered over the other. The balance control mainly controls volumes on each channel except digital delay. Speaker placement controls both volume and time alignment. I'd suggest two simple tests:
1. Switch speaker cables at the amp to see if the favoring side remains.
2. Extream toe in to minimize room interaction. Starting with speaker facing directly at you or in front of you.
Did you try reversing your speaker cables? For almost a year my left channel was weaker than the right. I blamed the source, the processor, the interconnects, and the amp. Finally I bought an integrated amp and still the left channel was weak. That left me with the speaker cable doubting, so I reversed it. Its fine now. You might give it a try.