SDA right/left and a balance question

Ricardo · December 2005

I've got my SDA-SRS's located in their "final" place; 7 feet apart, 5 inches from the back wall, and the right speaker is 30 inches from the right wall of a 25 ft wide room; I really tried to get them more to the center of the room but was not possible without making other major changes, so they'll stay where they are.

SDA sounds great, and for the most part what should be heard at the center is right on the middle. BUT..I really have the feeling that the left channel sounds just a tad higher than the right channel. Not to the point that anyone else in the house can hear it, but it just doesn't sound right. I need to say that my right hearing is a bit "reduced", but I already know what that makes to the sounds in my brain, and what I was hearing here was definitely not a consequence of that. I turn my back to the speakers as a test and I confirm that the left channel (now to my right) is a tad higher.

I am 100% sure that all connections are ok, but I decided anyway to swap the speaker wires just to see what happened.

Two things called my attention:

1.- The sound "might" have balanced to the right... I say might because I still need to make a before/after test with the same material, but I am 80% sure it did.

2.- SDA still works with the right/left channels swapped; not as wide, but sound still projects to the outside of the speakers; I just mention this because I thought this did not happen.

So...the question is; where in my system could I have this balance weighted to one of the channels? I am thinking the pre or the amp, since I am hearing it with both sources. Any ideas of what to check or what to do?

Thanks.

McLoki · December 2005

If you break out the SPL meter and play the test tones built into your pre (or some you have burned to a disk) what are the volumes from the right and left speaker.

(Just remembered this is a 2 channel rig - burn some tones or white noise to a cd, unplug one speaker, hit play, record the volume on an spl meter - plug in the other speaker and repeat.)

So, does the SPL meter back what you are hearing?

Michael

Ricardo · December 2005

Good idea...hmmm...would a mono recording work here??? Not sure I would know how to burn a CD with what you are suggesting....well. not sure I have a mono recording either

McLoki · December 2005

For this test I would think you want more of a constant tone rather than music, but a mono recording would work for a ballpark guess at "is one louder than the other?"

Michael

McLoki · December 2005

If have have avia or video essentials it would have tones on them. (may have to hook up a dvd temporarily to your 2 channel rig)

Michael

Ricardo · December 2005

there you go; I have the sound & vision set up disc; will do that when I have some time.....

danger boy · December 2005

this isn't unusual at all. often times one of my channels will sound slightly louder than the other. it's usually the right channel that is louder. I turn down that channel on the amp to match the left. and everything is good again. it seems to happen only on occasion or with different types of music. I don't think it's any problem with the amp or pre amp. it's just sometimes weighted to the right now and then.

bikezappa · December 2005

Put a mono recording on and use the balance control to make the sound come from the middle.

Mono recording=NPR on FM.

Ricardo · December 2005

No balance or individual level controls....yet..

F1nut · December 2005

I'd say it's room acoustics.

Ricardo · December 2005

F1nut wrote:

I'd say it's room acoustics.

I've thought that could be a reason; you think that the fact that the right speaker is closer to a wall can create this effect?

Well, whatever it is, the JBL Urei I'm getting from Russ with level controls will help compensate

okiepolkie · December 2005

Maybe I am learning something here. My suggestion would have been room acoustics as well. What does the "closer" wall have on it? Your first point of reflection may be reinforcing the sound wave, making it sound louder. You may have to put an accoustic deadening panel(doesn't have to be elaborate) on that wall to help even out the sound.

Every place I've lived in the past 5 years has had this problem. My best solution(aesthetically pleasing to the wife) was to put a bookcase with several objects on it to diffuse the sound. The left channel still sounded a little bit different, but it did even out considerably.

Zach

okiepolkie · December 2005

If at all possible, try to change something in the room before you try to change something electronically. That way you don't run the risk of changing the actual material, and only the way you hear it.

F1nut · December 2005

HTrookie wrote:

I've thought that could be a reason; you think that the fact that the right speaker is closer to a wall can create this effect?

That's what I'm thinking.

scottnbnj · December 2005

HTrookie wrote:

you think that the fact that the right speaker is closer to a wall can create this effect?

Well, whatever it is, the JBL Urei I'm getting from Russ with level controls will help compensate

that would do it. this might be one instance where a coat rack would be a more technically sound fix than hardware. if it works, then think about real treatments.

)

scottnbnj · December 2005

doh! too late.

)

Ricardo · December 2005

On the closest wall (to the right, and it is not reinforcing the sound....I hear the left channel a tad higher) we have the walk out glass slide door; it has vertical blinds, and I've tried to hear differences playing with the blinds (open, closed and at different angles) and I cannot hear ANY difference. I am starting to think that my right hearing loss might be getting worst...

Anyway, thanks everyone for the ideas; I will try the SPL test, though the difference I'm hearing is so small that I'm not sure I'll be able to spot it with the SPL meter.

Oh well...a few months ago I wouldn't have noticed any difference....I guess this is the price for getting a little serious about listening

F1nut · December 2005

I don't think the wall to the right is reinforcing the sound, rather it's killing the sound.

Ricardo · December 2005

F1nut wrote:

I don't think the wall to the right is reinforcing the sound, rather it's killing the sound.

I know...I mentioned it 'cause Olkie said that.

It's all good; thanks again everyone.

BobMcG · December 2005

CHESKY Records has an excellent test CD (CHE151) they put out in 1996 in conjunction with Stereo Review it's a quality Gold disk that used 128x oversampling called GOLD STEREO AND SURROUND SOUND SET-UP DISC. It has a lot of good tests on it. I got mine back in 1996 and just did a search and found they still offer it.

http://www.chesky.com/core/details.cfm?productcode=CHE151&category=1

BobMcG · December 2005

...yes, they have one for DVD 5.1 too. I haven't tried this one.

http://www.chesky.com/core/details.cfm?productcode=CHDVD221&category=1

Tour2ma · December 2005

HTrookie wrote:

I am 100% sure that all connections are ok, but I decided anyway to swap the speaker wires just to see what happened.
Two things called my attention:
1.- The sound "might" have balanced to the right... I say might because I still need to make a before/after test with the same material, but I am 80% sure it did.
2.- SDA still works with the right/left channels swapped; not as wide, but sound still projects to the outside of the speakers; I just mention this because I thought this did not happen.

First, just to be sure, when you say "higher" in your initial post, are you meaning louder?

Second, did you ever redo the wire swap as you mention in point 1? It's kinda key to this whole effort...

Third, your observation in point 2 is common in my experience. Most SDA rigs I have heard tended to have greater width to one side.

Ricardo · December 2005

Bob,

Great tip there; I ordered one....

Tour,

-Yes, I meant louder;
-I placed the wires back where they should be, but have not made any test with the same material; I'll wait for the test disk.

Thanks.

dudeinaroom · December 2005

In my cheappy setup, my dight 2b is closer to the wall than my left speaker, and my left channel sounds a little more bright(not louder) than the right. Also not to help matters any, my receiver's left chanel(only when in surround modes) is a little louder than the rest(don't worry, I hate playing 2 ch. audio in suround). If your running sepperates, you might want to check your gain levels on your amp(s), Or your receiver my be biased a little more to the left chanel.

danger boy · December 2005

what amp are you using? Do you have another amp you can swap out with it? How old is your amp? It may be time to get your amp serviced. My tech tells me it's not that uncommon for one channel to sound louder than the other channel in a stereo amp. Basically it needs to be serviced.

good luck, I'm out of ideas.

SCompRacer · December 2005

Along with tones, the Rives Audio Test CD 2 has some recordings for audio testing. IIRC, track 68-72 has a recording in stereo, mono, right and left channel.

SDA right/left and a balance question

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