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Please help, obsessive audiophile question

Ok, I did something really bad to myself, I got the XLO test CD. What I discovered was a channel imbalance, that, I think, is due to my room. Here is what I did:

First, using a laser, I perfectly centered my speakers in the room, and dialed in an equal amount of toe in on both sides. Also, again using the laser, I checked for dead center on the listening position and dead centered the components between the speakers.

Next, with the balance control centered, I ran the 315 khz test tone on repeat, and measured the voltage at the amp terminals. The voltage was nearly perfectly even. I repeated this at several volume levels, and usually was within a few percent. What ever variation occured between the channels was randomly split between left and right.

Next, the balance test on repeat. With the lights and my eyes closed, I used the remote to adjust the balance on the preamp to center the voice. I started out in the centered, extreme left and extreme right positions, and did my best to make sure I was unaware of how much adjustment I was dialing in. I repeated this multiple times, and got perfectly consistent results. I end up with the balance control turned about 4 "taps" to the right, which translates to a 10% voltage in favor of the right channel at 315 khz. I do not have a sine wave generator or ocilliscope, so I can not verify this over multiple frequencies, but my "aural" measurements have proved to be very consistant.

I adjusted a few moveable items in the room, but, due to some furniture that can not be moved, I think I am getting more reinforcement from the room on the left side.

So, what to do? Will this balance adjustment adversly affect my tube amps? Will one side go through tubes quicker? Should I try to move one speaker back? If I do move the one speaker back, will I adversly effect the time alignment between the two speakers? Or should I stop stressing and just leave the balance control off center.

I know it sounds compulsive and weird, but it sort of bugs me to see the balance control not dead center. Again, this IS an obsessive audiophile question;)

Thanks in advance for all your thoughts.

Ron
rlips
sean
6,229 posts
 
Believe it or not, i've listened to systems and found major problems that the owner's were completely unaware of. One system had a blown midrange driver in one speaker and another system had one of four woofers dead ( two woofers per speaker ). Neither owner was aware of this until i pointed it out. As such, it is quite possible that you could have a driver(s) that is completely dead or "softer" than the one in the other speaker. Someone else i know ran into something similar to your situation and after doing some testing, found that one of the tweeters, even though it was still working, was -3 dB's down from the other tweeter. Needless to say, he was quite shocked to find this out. Sean
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zargon's avatar
zargon
453 posts
 
It is not uncommon for rooms to have an asymetrical response. This is especially evident in rooms with a door way or hall off one side, or in L shaped rooms, or rooms with a fireplace on one side and not the other. If you test your room response it is wise to test the R and L channel alone at the listening position. You might be surprised at the differences. That being said, if the channel imbalance is not evident to you except when running the test, it is not worth worrying about. If it is evident, then you can move the speakers or the balance control to compensate.
zoya
119 posts
 
A shot of black label or single molt will do wonders to equlize the balance.
colitas
150 posts
 
Rlips, this may seem naive, but have you checked your phasing. This did the trick with my Maggies, the left speaker was hooked up wrong (+ & - reversed). This made up the difference. To do the ear thing I think you need absinthe, I hear Van Gone was on it at the time.
rockvirgo
587 posts
 
Rlips, since you're already committed to moving the speakers, while you're at it try this traditional balancing tweak: set the speakers directly facing each other one inch apart. Wire one out of phase with the other. Play a monaural selection and dial the balance until the sound becomes quietest. At least then you'll know where the system itself is in balance.
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