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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
6,231 posts
 
Sorry, i didn't take notice that you had your system posted with pics and that you were running stat's. You have a very clean looking installation.

It is quite possible for one panel to have higher output than the other. Running a mono disc and facing the speakers together won't be of much help if the non-linearity from speaker to speaker varies with frequency. Just as one speaker is louder in a specific frequency range, it might be quieter in another. Depending on how wide the variances are from speaker to speaker, the frequencies involved and the volume that you perform this test at, finding where it nulls might not give you the results that you think.

As a side note, do you sit dead center in the sweet spot? My Father has a tendency to sit off to one side as he finds the corner of the couch to be more comfortable than the middle. Some people wouldn't think twice about something so obvious, so i ended up having to pull the couch over to one side to counter-act this. He knew that he wasn't getting all the imaging and soundstage that he could by sitting off-axis, but he didn't think it was as drastic as it really was. Sean
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dlwask
270 posts
 
For what it's worth I had a similar problem in my room with channel/loudness balancing. My pre-amp has no balance controls though so I solved the problem by moving my right speaker back (which was the louder of the two) a mere 1/2 inch...presto problem solved.

Prior to that little 1/2 inch move my room was set up perfectly symmetrical...I measured and remeasured many times.

A symmetrical set up is a good place to start, then listen to make final adjustments...and then suffer knowing that your right speaker is 1/2" different from the left!
fefer77
37 posts
 
it might be the door in back of your listening position. do you usually listen with the door open or closed? i have the same issues as you and it was the room.
rlips OP
105 posts
 
Newbie: I thought about that, but my wife hears it too, it could be that the problem is contagious? *grin*

Sean: Oh no! I was going to do the out of phase check this evening, you are saying it might not work? Maybe I will check with ML. Although, If I just switched the speakers, and the problem stayed the same, I guess we would know its the room, as we already eliminated the amplification chain.

As fas as sitting in the middle, yes, asn I hate to admit this, but I checked it with the laser, which ended up right on my nose. I know my fellow audiophiles will only partially think I am nuts...c'mon, fess up, someone out there has done this.

Dlwask: I am leaning towards your solution after verifying it is not a speaker problem. If it is a speaker problem, I will try to get it fixed. Thanks for the encouragement, your right, a little part of me will suffer if it is not perfect, but I can deal with that if it sounds good.

Fefer77: Yep, the door is ALWAYS closed. I actually replaced the original door with the solid wood door (and spent forever staining the darn thing) in order to get better sound.

I will report back after moving the speakers.
zoya
120 posts
 
Rlips, I didn't realize that you have a picture of your setup until I read Sean's comment. I always try to look for most abvious - your plants behind speakers are not the same size, did you try to swap them around?
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