No problem Tom, it has been a learning experience. You are correct, small differences in placement seem to make a HUGE difference.
I already have heard the sound of my room without the acuostic panels, simply awful, like the inside of a drum.
In my room, with my speakers, the ASC panels make for what I percive to be better sound. Obviously, this was not the case for Geoffkait, and his experience in his room with his equipment is perfectly valid. |
Suppose I should have read all the posts and responses before posting my own response to the intial thread..Tom |
Panel based speakers are quite variable in response and hence balance and image.So has been my experience of ownership..If your room is perfectly symetrical in geometry and placement of sound panels, then I would look towards the speakers themselves..How do the speakers audibly align playing a mono cd?..Tom |
Geoffkait: Different room acoustics will require different speaker placement for optimum results. Having optimized the speakers for the acoustics of the room with the panels and then pulling the panels will change the entire presentation and in-room frequency response. Therefore, you're suggestion would entail a LOT more work for most installations if trying to keep things on an apples to apples basis. Doing anything less than the above would provide skewed results that aren't worth the time or effort. That's because they would only lead to further confusion in most cases. Sean
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slap echo can seem worse than it is, there are worse things that could happen. Attempts to cure slap echo often result in killing the "openness" of the sound. IMOM the panels can do more harm than good. I still have several panels here, but not in the room :-)
If it were me, I would take all panels off side walls and put in another room temporarily. See how the room sounds w/o them. Then bring back in one or two at a time to see how they affect sound. |
Geoffkait, do you mean the panels on the sides of my listening room?
I had the system without them, it was pretty bad, as I had a tremendous slap echo.
Would there be a better way to deal with slap echo? I am curious, as I always am willing to try to tweak the room.
Thanks,
R |
You're prob. not going to want to hear this one, but IMHO the panels - even one or two - can have dramatic (negative) influence on the sound - esp. soundstage, balance, transparency. I always prefer the sound w/o any panels in the room, tho' I really wanted the panels to be "magic." |
Geoffkait,
Yes, I have spent a fair amount of time listening to that one. It is very helpful. |
Just in case you haven't tried this, track 3 on XLO CD is the best channel balance and soundstage focus track (assuming you do not have a problem somewhere along the line). The objective of the Out of Phase track 3 is to obtain perfectly diffuse sound in the room as heard from listening position - i.e., the sound should appear "to be coming at you from all around the room." In order to obtain this perfect focus/balance you need only to move one speaker a little at a time, i.e., you cannot necessarily rely on speaker symmetry, etc. to obtain optimum results. An inch or so movement of one or both speakers can make all the difference. |
I implemented the toe in procedure recommended by ML, and found a Huge improvement. Balance is now dead
on, speakers are symetrical in the room.
As a side bonus, the new toe in has nicely opened up the soundstage, which now extends wider and deeper. |
I spoke with the speaker manufacturer today, and learned a few things.
1st, the panels are hand formed, and can vary in curvature. Accordingly, there is a special procedure used when setting the toe in which will compensate for the differences in curvature. The way I set the speakers up, using the lower cabinet, can result in a difference of toe in on the panel.
2nd, my speaker can vary as much as 1.5db from the other and still be considered "in spec" This was very surprising.
I will try the revised set up instructions and report back. More confusion. |
Glad that you were able to work things out and come to some type of a conclusion.
Personally, i would not let Martin Logan off the hook without having the problem corrected no matter what. Not only are the speakers not performing correctly in terms of balanced output between them, it is quite possible that one or both is skewing what you are hearing in terms of frequency and transient response. If both speakers respond to the same signal in varying manners, they will excite the nodes in the room differently. This is true due to the non-symmetrical loading characteristics that are present in most rooms.
Given that swapping sides with the speakers helped to balance things out tells me that the speakers are not loading up the same due to variables in the room. Changing the loading conditions changes the nodal points in the room, which will in turn highlight or minimize output in specific regions. The fact that moving the speakers allowed you to achieve proper balance confirms that there is both a problem with the speakers and that the room isn't quite as linear as you think. Believe me, you are NOT alone in this, even with room treatments.
A good test for something like this is to play a slow frequency sweep as can be found in the Ayre Acoustics "Irrational But Efficacious" CD or on the Cardas LP. Sit dead center in the sweet-spot, turn off the lights and listen to the frequency sweep with your eyes closed. In a perfect world, the sound will remain perfectly centered between your speakers if room acoustics / speaker loading are optimal. In the real world, you will hear the image shift from from side to side as frequency varies. The more consistent that the image stays centered, the better your room / speaker interface. My guess is that ANYBODY that puts their system through this test WILL hear the image walking around. At some points, you can literally hear ( it almost seems like you can see & pinpoint ) the image as it moves around the room. In some systems that i've done this in, the sound is literally flying around the room like a helicopter bouncing off the walls. Cool for special effects but horrid as far as audio goes.
Not only will the image walk around, listen to how consistent the volume of the tone remains. My guess is that you'll hear some spots that are "hot" and others that drop out quite noticeably. The nodes and reflections in the room effect every aspect of the sonics that you hear, both in amplitude and in phase. Doing this test will tell you just how non-linear your room / system is in terms of both amplitude linearity and frequency response. Bare in mind that the results are only valid AT YOUR SEATED LISTENING POSITION. If you want to see what i'm talking about in terms of listening position, run the test several times and then scoot over a few feet in either direction. You'll get completely different responses with each move.
Once you've done this in stereo and you're very disappointed, try doing the same test in mono. You'll be amazed at how much smoother the response is, both in terms of amplitude and frequency response. The image will remain centered most of the time and the peaks and dips in amplitude will have evened out quite a bit. This is the type of response ( or even better ) that you're shooting for in stereo mode. All i can say is "good luck" when trying to achieve this : ) Sean
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I see my last post did not make it?
OK, here is the report:
Sean was pretty much correct, it was a combination of 2 things:
1) One speaker is slightly louder than the other
2) The room is re-enforceing the left side.
As soon as I switched the speakers, the image moved to the right side. However, it was much closer to the center, and only required half the correction to bring it back left to center.
I moved the right side back 1, then 1.5", and the system is now centered.
So, one speaker is slightly louder than the other, and the room has an asymetrical response. I will call the speaker manufacturer to discuss this, but I am not to worried at this point, as I have the system SOUNDING good. If there is an adjustment, fine, but if not, I think I can live with this.
Thank you all for your thoughtful responses, it never would have occured to me that one speaker would have a slightly different response.
Best Regards,
Ron |
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? |
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. |
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. |
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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FWIW, I've had this problem, perhaps to a slightly lesser degree, using tubes and SS with dynamic and electrostats, in several home. Drove me crazy (no snide comments please)because its not constant. Some days its spot on - some days I can center the image by shifting my butt a few inches and turning my head toward the right speaker. I finally figured out my problem - its my ears. If you haven't already done so see an audiologist and have you hearing checked. |
Here is a link to 2 cad renderings of the room that I did when I designed the setup. I think it gives a better picture. The opening had a door, solid wood core, not shown. roomroom2thanks |
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! |
Pmotz: I tried the plant thing, and it helps somewhat. It does not get rid of all the problem. The photo represents plant placement before the tweaking, they are now reversed.
The left wall is an exterior wall, and is insulated. The right wall is an interior wall, and is the same construction, but not insulated. This could very well be an issue. It is frame construction, but the exterior wall would have drywall, insulation, plywood, stryofoam and siding. The interior wall would have drywall, airspace, and drywall.
Thanks for you ideas, they may be helpful....."honey, we have to tear down some walls now" Actually, at this point, she would just laugh.
Best,
R |
A couple of suggestions based on the photo of your system. Try swapping the plants from side to side to see if that shifts things. They are different sizes and the Martin Logans do have a significant back wave adding to the sound. The other thing is the construction of the room, based on the photo the front part of the room is very symmetrical (with the slight exception of the plants) but is the construction of the two side walls the same? If one is insulated and the other not or one solid (concrete or block) while the other is framed it can make a difference. These may seem like wild ideas but you've ruled out a lot of the more obvious things. With respect to items behind the listening position (out of the photo) you could try adding some diffusion to eliminate reflections that could be reinforcing or cancelling specific frequencies. Your comments on how the tube trap improved things indicates that could be a problem. A small room could emphasize this problem, what are the dimensions of the room? |
Balance control? I don't even have a front panel power switch.
Although the manufacturer was gracious enough to provide me a means in which to adjust the volume. |
I suffer from this same problem and I've always made the adjustment with my balance control. This past year I made the leap to tubes. I've bought a Music Reference RM9 amp and a RM5 MkIII preamp and I'm lovin' em! I didn't realize that I was causing uneven tube usage until I read this thread. Can anyone elaborate? How soon will this problem manifest itself? Thanks to this thread I think I'm going to play with my speaker placement, I don't want to mess with my tubes!;)
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Rock: LMAO thinking about the driveway thing, yeah, my speakers and a couple hundred pounds of tube amps in the driveway. They would lock me away.
I am going to run the test tonight, my wife is going out with the kids, so I can happily stress out;)
R |
Rlips, if your speakers are not mirror images of each other getting them to cancel may be a challenge. As long as they face each other as closely as possible it probably doesn't matter where in the room they or you are. You'll know when you've got it right. If you really want to obsess take them out in the driveway into "free air" and amuse the neighbors. Just don't blame me if you smack them into each other during alignment! Give it a try and let us know if it confirms your earlier balancing acts. |
Thanks again for more great ideas, please keep them coming.
Sean: The speakers are stats, (actually hybrids), so I imagine either it works or does not? It is possible to easily switch only the panel section of the speakers, so I may try this. I suppose the internal step up transformers could have differing gain. My hunch is that the room is the culprit, but if one speaker is indeed louder, it may be that switching the locations could help, especially if the louder speaker is now in the location that is receiving the room re-enforcement.
Zargon: It is evident, mostly in that the vocals always seem to come from left side of the sound stage. If I close my eyes and "point" at the vocalist, I almost aways point at the same spot, about 20% over to the left.
Zoya: Thanks, I don't know if the pun was inentional or not, single "molt" vs. single "malt". molt: v.tr. To shed or cast off (a bodily covering) hehe
Colitas: Yep, the system passes the phase check with flying colors. Is there an audiophile brand of absinthe? One that comes in a non resonant bottle????
Rockvirgo: I will try that. A question about that procedure: should I place them as close to the center as possible and listen from my seating position? Or should I listen close, as this is just to determine if the amount of energy emitted from each speaker is equal?
Thanks |
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. |
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. |
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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A shot of black label or single molt will do wonders to equlize the balance. |
Sean,
Thanks for your post. I think I am going to lug my speakers around, to get to the root of this. I was trying to eliminate the idea that it might be equipment related, and, frankly, I did not really think that it could be a speaker output imbalance. If it does turn out to be an speaker problem, it should be easy enought to fix, as they are only a year old.
I will report back. |
Some good comments above.
A small amount of channel imbalance that varies with volume is quite normal. Most mass produced potentiometers don't track both channels identically and will "wobble" back and forth slightly as the value is altered. If you want to fix this, get ready to install precision built hand assembled stepped attenuators.
The fact that you showed even voltages at the speakers says that the signal amplification chain is working relatively linearly. This leaves only three reasons for the imbalance that you are experiencing.
1) Room loading conditions are causing image shift due to various reflections and cancellations
2) One of your speakers is working differently from the other causing a variance in frequency response / imaging.
3) Both you and your wife have similar hearing disorders.
My guess is that it is probably either 1 and / or 2 with 3 being a WAY distant third. There is a very easy way to narrow this down. As mentioned above, you can try swapping speakers from side to side. If the balance remains tilted in one direction, it is the speaker / room acoustics interphase that is creating the problem. If the image shift reverses itself, you've got a problem with the speakers.
If the speakers are too large to move around and easily position by yourself, you might want to try doing a nearfield measurement using a frequency sweep to verify relatively even output across the audible band. Taking readings further into the room and away from the speakers may confuse the issue by the reflections / cancellations coming into play. Obviously, small variances from one speaker to the other are to be somewhat expected due to non-precision microphone placement from speaker to speaker. Rather than look for huge abberations, which you hopefully won't run into, keep an eye out for specific trends.
Until you can get things straightened out, i see no problem with using the balance control to maintain the proper center image. Just bare in mind that if you are running any tubes in the system, one side is getting more of a work-out than the other. This can be somewhat alleviated by swapping tubes from side to side after a given period of time, etc.... This is not that big of a deal for SS gear, but you could always swap cabling around in order to try and achieve "more even wear" if a long term situation.
If it turns out to be the speaker / room interphase, sound treatment panels can work wonders when properly applied. I just got done doing some major work on my Dad's system / room. I have gotten no less than three phone calls from him in two weeks just for him to say "THANK YOU" for all the work put in and the results achieved. I've still got a ways to go with his system, but now he understands why i always complained about how bad his system sounded, especially in certain aspects of operation. Not only did these efforts get him far better results with more consistent sound, it bought a lot more respect for my opinions and ears from him. Before this, i was just his big-mouthed older son. Now i'm his big-mouthed older son that should have taken care of these problems years ago. I might have done so if he wasn't so "pig-headed". To be honest, i was only able to make the changes that i did because he was away from the house for an extended period of time : ) Sean
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PS... The type of investigative research that you are doing is the first step towards obtaining truly excellent in-room response with great leaps towards transparency and improved sonics. I am glad to read of someone putting forth the time and effort that you are. I just hope you continue down this path as you will not regret it. Nor will your wife, even though you may drive her crazy initially : ) |
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. |
Oh, Feffer77, I missed part of your response. Behind my listening position is a semi round piece of furniture on the left side, and a solid core wood door on the right. I am pretty sure this might be the cause of the imbalance. I moved one of my tube traps in front of the furniture and it helped. |
Thanks for the responses so far, it helps to know there are others like me out there!
Fefer77: I think the gain is ok, as I measured the outputs of the amps to be fairly equal. I already switched the amps around, no change.
Electric_monk (great moniker, btw): I can't do that, I have really short cables, the advantage of monoblocks;) I will probably lug, but I will have to enlist some help, so I can't do it right away.
Deano: I might end up doing that, but I was concerned about messing anything else, as I have the rest of it dailin in nicely. I think I will try it though, as I can always go back.
G_m_c: I agree, but the question is, where exactly should I begin the cut? Do I cut off the entire thing, or try to balance it by just cutting a little at a time? Should I use a stainless steel knife or would that give the system a "metalic" sound? Should I cryo the ear? Sorry, I digress, but at least I am smiling now. |
Van Goth would have simply cut off the imbalanced ear. |
Driver, I thought about that as well, but, in order to make myself totally wacko, I gave the remote to my wife. She also dialed in about the same balance, shook her head, kissed me on the cheek and said "I guess I will see you at what, about 2 am tonight??" At least she knows where I am at 2 am;) |
Even though each speaker may be placed EXACTLY the same distance from the listening position, the room's shape and funishings may influence apparent channel balance. Move the speaker whose volume is down, closer to the listening chair. An inch and a half did it for me. Good luck.... |
Swap the speaker cables left to right and keep the speakers the same position. I know it aint perfect but it should answer the question of whether or not it is downstream from the speakers or "at" the speakers. If this doesn't change anything then get to lugging. |
The possibility exists that your hearing is better in your left ear over the right, so you need the balance adjusted to the right to compensate. I know in my case the left is better than the right. |
you might be getting more gain from the left channel monoblock - switching amps would prove it. it might be the room although in your picture the room looks quite symetrical - what's going on behind your listening position? i probably wouldn't bother about it though - like Khaki8 says that's why you have a balance control. |
Khaki8, I know, I know, but I was wondering if there was something else I should try and address first.
Me: I guess that could be, I should probably switch them. Oh boy, that is going to be a project, those things are way heavy. |
maybe one speaker is playing louder than the other is |
In 20 years, you'll regret the time spent fretting about this. In the mean time, kknow that we all empathize with your pain, and just try to let it go. Be thankful that your system HAS a balance control. I would just leave the balance control off center. If it really worries you, maybe try alternating channels on your amplifier, so that first one side is right for a mointh, then switch it to left for a month. If you've achieved good sound with the setup you have, I wouldn't move stuff around. What's the point of having a balance control if you don't use it? |
I think that is what the balance control is for! |
