Placing a second pair of speakers

[Jax]

Ok, so I did a highly unscientific test today by holding up a speaker next to one of my already situated LSR28P's. I was trying to determine two things:

1 - If the electromagnetic field (if that's what it is) shared by the JBL and the speaker I was holding would warp what's on my CRT monitor in any way. It didn't, and it was good.

2 - If I could hear any change in what the JBL was doing while it had a new neighbor hovering next to it. I couldn't, and it was good.. although since I was standing almost behind the JBL, I wasn't really in a good spot to hear any changes... and the passive speaker I was holding wasn't hooked up to anything. hmmmmm

And then, a complication came to mind:

Does placing another speaker between the JBL and the side wall change anything in the following formula?

The distance from the center of the woofer face to the side wall is:
Room Width times .276 (RW x .276)

That was how I placed the JBL's and they sound great right there. The room is 11.5' wide, so they're about 3.x' (I forget exactly) from the side walls, and still well within their imaging range.

So, if I setup the second pair of speakers where mentioned, will they alter the equation by becoming a boundary (like another wall) even though they will be almost in the same diagonal axis as the JBL's?

I'd love to use these old favorite boxes for another reference, but I'll hold off on ordering that 2nd pair of monitor stands until I have a better idea of what I'm doing.

TIA for any help!

[tINY]

It depends on the size of the cabinets. For most cabinets, the directionality of the tweeter on the main speakers will control the dispersion of the higher frequencies.

Then, if the size of the other cabinet is reasonable, it won't affect the low frequencies that radiate in that direction enough to worry about.

http://hyperphysics.phy-astr.gsu.edu...d/diffrac.html



-tINY

[Jax]

Originally Posted by tINY

It depends on the size of the cabinets. For most cabinets, the directionality of the tweeter on the main speakers will control the dispersion of the higher frequencies.

Then, if the size of the other cabinet is reasonable, it won't affect the low frequencies that radiate in that direction enough to worry about.

http://hyperphysics.phy-astr.gsu.edu...d/diffrac.html



-tINY

Thanks for the link - it reminded me of not having not paid enough attention in physics class.

The different speakers are fairly similar in size. The other speakers are about 2-3" taller and maybe 3" less wide than the JBL's. The biggest difference is the depth of the cabs, where the JBL's are about 6-8" deeper.

Are the two different speakers similar enough in size that they won't detrimentally affect eachother in terms of diffraction?

And I'm still not sure of the answer to my main question about whether or not placing a speaker between the JBL and the wall obscures or negates the point of having placed the JBL's according to the formula: The distance from the center of the woofer face to the side wall is:
Room Width times .276 (RW x .276)

Doesn't the new speaker become a new boundary in some way? Or are the cabinet sizes similar enough that it shouldn't matter?

Thanks again for your help!

[tINY]

If you put the speakers so that the sides are touching, you effectively make a larger baffle for both speakers. This will likely change the midrange response a bit.

But, since the formulae for "perfect" speaker placement are appoximate anyway, I'd separate the cabinets by about the width of the face (or a little more) and split the differece on placement.




-tINY

[tINY]

Or you could separate them vertically.....




-tINY

[Jax]

Hmm, I don't think I want to get into hanging the speakers above the JBL's. Just wouldn't feel right to me.

Which speaker face did you mean to use as the reference for spacing them apart from eachother?

When you say to split the difference on placement, do you mean you'd leave equal space between each speaker and the same amount of equal space between the outside speaker and the wall?

Thanks again!

[tINY]

The face is the side the drivers are mounted in

Split the difference: Put the center of the space between the speakers in the voodo position.




-tINY

[Jax]

Originally Posted by tINY

The face is the side the drivers are mounted in

Split the difference: Put the center of the space between the speakers in the voodo position.




-tINY

Yes, but the drivers in which speaker is what I was asking.

Voodoo position? The best sounding place, I take it.