Toeing in my towers

[Gimpy Ric]

I have a small problem with the acoustics in my room. My left front main does not have very much free space to its left. My right front main has a large amount of free air space to its right.

I have towed in the Main's instead of having them just face straight. This seems to have helped. The tweeters are not facing straight at me, as I did not want to get the speakers too much off axis.

Oh boy, makes me wish that I had just kept my 632 LR bookshelves. Can you guys give me any help?

Thanks in advance,

Gimpy

 

[WmAx]

I have a small problem with the acoustics in my room. My left front main does not have very much free space to its left. My right front main has a large amount of free air space to its right.

I have towed in the Main's instead of having them just face straight. This seems to have helped. The tweeters are not facing straight at me, as I did not want to get the speakers too much off axis.

Oh boy, makes me wish that I had just kept my 632 LR bookshelves. Can you guys give me any help?

Thanks in advance,

Gimpy

The solution is simple: Use two of the 2' x 4' x 4" thick full range acoustic absorbers placed side by side to create a reflection free left wall to more closely match the vast open right side. Be sure the absorbers used have a full range cloth cover, as some have a cloth that reflects at upper mid and treble frequencies, which is not at all desirable in this situation.

-Chris

 

[3db]

The link below is a thread which shows a do it yourself project for constructing acoustic panels. I tried it and it worked well for me.


http://forums.soundandvisionmag.com/audiovideo/board/message?board.id=40&thread.id=27061

 

[mazersteven]

I have towed in the Main's instead of having them just face straight. This seems to have helped. The tweeters are not facing straight at me, as I did not want to get the speakers too much off axis.

If I'm not mistaken. You mains shouldn't be facing straight ahead into the room. You should play around with toeing them in, and out till you find the best position for them. Sometimes that position might even be right at the sweet spot.

 

[WmAx]

The link below is a thread which shows a do it yourself project for constructing acoustic panels. I tried it and it worked well for me.


http://forums.soundandvisionmag.com/audiovideo/board/message?board.id=40&thread.id=27061

I skimmed the link - and it had two issues that I have a problem with:

(1) 1" rigid fiberglass was specified. This is not sufficient. Use at minimum 2", or ideally 4" thick material in order to have a wide band of absorption.

(2) Suggested using burlap as an acoustically transparent material. Not a good choice for near reflection points -- ordinary burlap will reflect upper midrange and treble. I recommend that you take a portable radio and headphones to a fabric store. Tune it to a 'pure static' station and listen to the static with the fabric between your ear and headphone vs. no fabric. It should sound nearly the same - if there is noticeable 'dulling' of the static(white noise), then it is reflecting the treble range.

-Chris

 

[mazersteven]

I skimmed the link - and it had two issues that I have a problem with:

(1) 1" rigid fiberglass was specified. This is not sufficient. Use at minimum 2", or ideally 4" thick material in order to have a wide band of absorption.

(2) Suggested using burlap as an acoustically transparent material. Not a good choice for near reflection points -- ordinary burlap will reflect upper midrange and treble. I recommend that you take a portable radio and headphones to a fabric store. Tune it to a 'pure static' station and listen to the static with the fabric between your ear and headphone vs. no fabric. It should sound nearly the same - if there is noticeable 'dulling' of the static(white noise), then it is reflecting the treble range.

-Chris

I think you should post your thoughts on the subject over on that thread. It would be beneficial to others in gaining knowledge.

COF now under the name IrritateGuy ad you should have a lot in common. He is into internal bracing, DIY projects. In fact he is the reason SVS added internal bracing to their PB10-ISD subwoofer after he reviewed, measured, and tested it.

 

[3db]

I skimmed the link - and it had two issues that I have a problem with:

(1) 1" rigid fiberglass was specified. This is not sufficient. Use at minimum 2", or ideally 4" thick material in order to have a wide band of absorption.

(2) Suggested using burlap as an acoustically transparent material. Not a good choice for near reflection points -- ordinary burlap will reflect upper midrange and treble. I recommend that you take a portable radio and headphones to a fabric store. Tune it to a 'pure static' station and listen to the static with the fabric between your ear and headphone vs. no fabric. It should sound nearly the same - if there is noticeable 'dulling' of the static(white noise), then it is reflecting the treble range.

-Chris

I used cottomn fabric that I could see thru when held up to light. I did notice an improvement in sound in my HT room once I hung these panels up.

Maybe you should discuss your ideas with Irate Guy (COF) and once the two of you have reached a consensus, new DIY plans can be posted both here and at forum at Sound & Vision.

 

[WmAx]

I used cottomn fabric that I could see thru when held up to light. I did notice an improvement in sound in my HT room once I hung these panels up.

Maybe you should discuss your ideas with Irate Guy (COF) and once the two of you have reached a consensus, new DIY plans can be posted both here and at forum at Sound & Vision.

Assume mounting against a wall(Type A mount), a 1" piece of unfaced high density fiberglass board or rock wool board would have little effect upon frequencies under roughly 500-600Hz. Moving this to 4" thick would yield significant absorption down to roughly 100Hz. The 2" piece I recommend as a minimum would have substantial effect down to roughly 250Hz.

-Chris

 

[WmAx]

I think you should post your thoughts on the subject over on that thread. It would be beneficial to others in gaining knowledge.

COF now under the name IrritateGuy ad you should have a lot in common. He is into internal bracing, DIY projects. In fact he is the reason SVS added internal bracing to their PB10-ISD subwoofer after he reviewed, measured, and tested it.

I do not have an interest in posting at that forum.

-Chris

 

[3db]

I do not have an interest in posting at that forum.

-Chris

What about posting the consesus in this forum or are you opposed to the idea in general?

 

[WmAx]

What about posting the consesus in this forum or are you opposed to the idea in general?

What consensus are you referring to? I merely pointed out some physical details considering the information posted.

-Chris

 

[mazersteven]

I do not have an interest in posting at that forum.

-Chris

I knew that would be your answer.