Dissimilar Front Speaker Placement

[Bluespower]

I've seen it stated time and time again that you should NOT have your right & left placed identically (in relation to the side and back walls). What I have never read is how much of a difference is needed. If one were 2" out further from the back wall and 2" further away from the side wall, would that be enough to cancel out the competing sound waves? 6" & 6"? 12" & 12"?

[dknightd]

Interesting question. I personally like to have my speakers nearly symetrically placed in the room. I do like to have the distance from the side wall different from the distance to the front wall. Symetrically space speakers seem to have better imaging, but you have to be doubly careful they are not exciting the same room resonance. I'm curious what people have to say about this since I haven't put spikes on my speakers yet. I think the answer will depend on how, or if, the room is treated. I don't think there is right answer, just what is the best comprimise for your room and listening preferences.

[Nolan B]

I cant totallt answer this question, but I can say it can very from speaker to speaker. I have B&W 601 S3 speakers and 1 was placed very close to a back and side wall. When i upgraded all my speakers for B&W FPMs I noticed it sounded much better...and not just because FPMs are better speakers then 601s. I read in the FPMs manual that the case is specially design...hance the fact they are meant to be placed directly on a wall.

[Kal Rubinson]

I've seen it stated time and time again that you should NOT have your right & left placed identically (in relation to the side and back walls). What I have never read is how much of a difference is needed. If one were 2" out further from the back wall and 2" further away from the side wall, would that be enough to cancel out the competing sound waves? 6" & 6"? 12" & 12"?

It's a question of degree and of the LF extension of the speaker. However, 2" is probably inconsequential.

In one system, I have the L/R 4' from the sidewalls and 2.5' from the front.
In the other, I have the L/R 4.5' from the front wall and 2.5' from the sides.
Both were determined by experimentation and by RPG's RoomOptimizer.

Kal

[Karma]

HI All,
With a 2 channel stereo setup I generally dislike a pure symetrical arrangement in a room. Being symetrical, the room reinforces and interferes with the same frequencies from both channels resulting in lumpy response.

However, radical asymetry is also a problem mostly having to do with imaging and soundstaging. So my answer is to have a room with a little asymetry but still allows for precision imaging. I have never found a formula that will give the answers. It seems I am always relegated to experimentation and compromise.

Sparky

[Kal Rubinson]

HI All,
With a 2 channel stereo setup I generally dislike a pure symetrical arrangement in a room. Being symetrical, the room reinforces and interferes with the same frequencies from both channels resulting in lumpy response.

That assumes a lack of attention to room acoustical treatment and/or design, of course.

Kal

[WI Rotel]

I've seen it stated time and time again that you should NOT have your right & left placed identically (in relation to the side and back walls). What I have never read is how much of a difference is needed. If one were 2" out further from the back wall and 2" further away from the side wall, would that be enough to cancel out the competing sound waves? 6" & 6"? 12" & 12"?

This is news to me. Main speakers should be placed identically forming a perfect isosceles triangle with the listener. Different speakers react differently to how close they stand to the closest wall. As a rule, in a perfect world, 1 meter should be the minimum distance . In my case (XT) placement close to the wall makes the XT4 sound bass heavy, in my application I don't have a choice so to tame the bass I covered one of the ports with the supplied bungs. As to distance most surrond processors allow you to adjust the relative output of each channel (room EQ) so as to compensate for the real world.

[Kal Rubinson]

There are two issues here and the OPs wording is ambiguous to me on distinguishing them in saying "you should NOT have your right & left placed identically (in relation to the side and back walls)."

1. Both speakers are a different distance from the front than from the side wall but both speakers are placed with those same distances. This is a symmetrical arrangement which is good if the room is a good one in terms of dimensions and acoustics.

2. Each speaker is the same distance distance from the front wall and the side wall. This symmetrical arrangement is not good because the SBIR reinforcement for all walls and both speakers will be at the same frequency.

Kal


Kal

[Bluespower]

There are two issues here and the OPs wording is ambiguous to me on distinguishing them in saying "you should NOT have your right & left placed identically (in relation to the side and back walls)."

1. Both speakers are a different distance from the front than from the side wall but both speakers are placed with those same distances. This is a symmetrical arrangement which is good if the room is a good one in terms of dimensions and acoustics.

2. Each speaker is the same distance distance from the front wall and the side wall. This symmetrical arrangement is not good because the SBIR reinforcement for all walls and both speakers will be at the same frequency.

Kal

Kal,

I want to make sure I understand what you stated above.

I have 804s and the measurements I'm going to list are taken from the center front of the grill. Both left and right speakers are presently 31" from the back wall and 25" from either of the side walls.

IF I understood you correctly, the BAD condition would be if each speaker measured 31" from the back wall and 31" from the side walls.

It is OK (?) to have both left and right speakers placed identically as long as the ratio (distance from the back wall and the distance from the side walls) is not the same.

I must have misunderstood the reading I did that prompted the question. Always glad to learn...

[Kal Rubinson]

Kal,

I want to make sure I understand what you stated above.

I have 804s and the measurements I'm going to list are taken from the center front of the grill. Both left and right speakers are presently 31" from the back wall and 25" from either of the side walls.

IF I understood you correctly, the BAD condition would be if each speaker measured 31" from the back wall and 31" from the side walls.

It is OK (?) to have both left and right speakers placed identically as long as the ratio (distance from the back wall and the distance from the side walls) is not the same.

In principle, that's OK. I would like them a little more different but your ear (or your spectrum analyzer) are the judge.

Kal

[Karma]

That assumes a lack of attention to room acoustical treatment and/or design, of course.

Kal

HI Kal,
No it does not assume that. Even with the best treatment techniques one cannot overcome completely the the nodal problems in a room. Certainly proper treatment and speaker placement can help but not eliminate. Equalization may help but the sonic price is too high, IMO.

If you have followed my past posts you know I am as big an advocate of room treatment as anyone. As such I understand its limitations. Far better to have an fundamentally good room to start with. At least you have a chance for good and consistent sound.

Also, I am a strong follower of symetrical speaker placement with respect to the listening position. Lack of symetry here will take its toll on all sorts of spacial performance. My comment was a little misleading in that I was commenting on the placement of speakers in the room, not their relationship to the listener which, in my experience, must be precisely symetrical. Thus, I think we agree on that issue.

Sparky

[Kal Rubinson]

Yup, we agree on that. I prefer symmetry with respect to the room, too, in order to avoid imbalance in the surround field for stereo or, even, for multichannel. Of course, each room demands its own solution and rules-of-thumb don't always work.

Kal

[audioqueso]

http://www.cardas.com/content.php?area=insights&content_id=26&pagestring=Room+Setup