Near-wall home theater towers... does hefty wall treatment help?

[lunchmoney]

Ok so I'm looking to upgrade the mains in my home theater, which are currently Zaph SR71's, crossed at 80hz to a sealed Dayton 12".... the SR71's are fantastic, but I'm itching for something bigger... probably crossed lower to the sub, if I use the sub at all.

Looking to purchase pre-cut flat packs kits.... I'm considering Mini-Statements, Finalists, Solstice, CSS 2TD-X, and a few others, all of which I can buy flat-pack kits for.

One general question I have is about distance from the front wall, which is currently about about 10" with the SR71's... not great, I know... If I go with any of the above larger designs, this would go down to 8" or 9", since they really can't come out into the room much more.

I've got big 4" thick absorption panels behind each one (3M insulation, whichever the correct grade is, I forget).... They do wonders for imaging and detail, but do these panels help with near-wall issues? Or make them worse? I'm really not sure....

Are there any other flat-pack designs I should be considering because of this issue? Or will the above designs be ok with the wall treatment?.... think "no bigger than mini-statements". I just don't have the space.

Here is a picture of one of the SR71's with the 4" thick absorption panel behind it.



Thanks

[billfitzmaurice]

See Option 2:
http://arqen.com/acoustics-101/speak...-interference/

Other designs won't make any difference, unless their baffle step frequency is lower than the 1/4 wavelength distance to the wall. As for using no sub, when at the link scroll down to 'Bass suckout and listening distance from your rear wall'. The usual cure for that is having low frequency sources placed in the front and the back of the room. You can't do that if you don't have separate subs.

[lunchmoney]

See Option 2:
http://arqen.com/acoustics-101/speak...-interference/

Other designs won't make any difference, unless their baffle step frequency is lower than the 1/4 wavelength distance to the wall. As for using no sub, when at the link scroll down to 'Bass suckout and listening distance from your rear wall'. The usual cure for that is having low frequency sources placed in the front and the back of the room. You can't do that if you don't have separate subs.

Thank you!

Ok, well Option 2 says I should place them even closer to the wall, and I already have the absorption for this approach.... I was not expecting this!... Perhaps the SR71's would sound better that way as well, I'll try it out.

Of course I'll want to make sure that any future design doesn't have a port up against the absorption panel, but that shouldn't be hard to get around.

[andy19191]

One general question I have is about distance from the front wall, which is currently about about 10" with the SR71's... not great, I know... If I go with any of the above larger designs, this would go down to 8" or 9", since they really can't come out into the room much more.

The only fully satisfactory solutions are likely to be designs that include the presence of the wall. Few if any of your flat-packs are likely to do this and so it becomes more a question of minimising the degradation. There are of course other factors relevant to sound quality but it will be sitting there in the minus column nagging away.

I've got big 4" thick absorption panels behind each one (3M insulation, whichever the correct grade is, I forget).... They do wonders for imaging and detail, but do these panels help with near-wall issues? Or make them worse? I'm really not sure....

The rule of thumb is quarter of a wavelength for effective absorption which means from the baffle to the wall to effectively fill the main dip. There is a figure in Toole's book showing this. It is just about viable for a speaker on a shelf of a bookcase but not really for a speaker on a stand like the one in your picture.

Are there any other flat-pack designs I should be considering because of this issue? Or will the above designs be ok with the wall treatment?.... think "no bigger than mini-statements". I just don't have the space.

that limits the damage for a 2 way fairly well using appropriate design but to do a better job one really needs drivers on the front and side of the speaker.