Tips for Istalling In-Wall Speakers? (1 Viewer)

[John Karpiscak]

Hi everyone. I've just installed four Jamo 883 In-wall speakers and have begun audio testing in an unfinished room. No subwoofer or center channel just yet- next month.
The high and mid range seem to be well but I'm missing a lot of Bass. The speakers are placed between 2x4 studs with only 1/2" ply behind them (seperating other rooms). The walls vibrate a lot so I suspect that the bass is getting lost in the rear of the speakers and absorbed by the 'thin' walls to some degree.
I suspect that I will need more mass behind the speakers to reflect the bass outward more forcefully, but I am no acoustics expert. Any thoughts out there? Thanks!
John K
www.y2kfam.com

 

[Tim Ranger]

An installer I know claims that the only way to get decent quality bass from inwalls is to have some sort of separate enclosure built within the wall. Otherwise, as you are experiencing, the walls themselves radiate all kinds of out of phase energy that makes for real poor bass definition. You might want to try using a sub, and crossing over around 100Hz so your inwalls arent' really doing the low bass.

 

[BobRoulier]

John, I would suggest that you set all your inwalls to small and use good sub for your bass needs.


Bob

 

[John Karpiscak]

Guys: Thanks for the tips. I also did some checking on line and found out what I suspected: the in-walls are setting up counter-vibrations that dampen out the low end bass from the speakers.
Last night I started experimenting using an extra subwoofer (from a computer system) and turned the speakers from 'large' to 'small', and crossing over at 100 Hz. That helped out quite a bit. The On-Screen Display that the Harman Kardon receiver has made that easy. I'll get a better subwoofer next month.
Bit we are getting closer . . .
I'm also going to take your advice and build some separate enclosures for the front R/L in-walls using some 2x thick particle board and see (or rather listen) to what happens.
Anything else I should consider?
Regards,
jk3
www.y2kfam.com/theater.htm

 

[Tim Ranger]

Sounds like you've got it going John! Building the enclosures and adding the right sub should do the trick.

 

[William_Morr]

Last year, I installed a pair of M&K SW-95 as my main speakers in a new addition to our house. The speakers came with two pieces of acoustical foam. One piece surrounds the speaker, creating a "pseudo" enclosure. The second piece is a flat piece of foam that is placed behind the woofer to absorb the backwave that, if reflected, would serve to cancel out the bass. My walls are 2x6.

Even with the foam installed, the speakers start rolling off at 100 hz as measured at the listening position.

A sub makes all the difference in the world for inwalls.

 

[John Karpiscak]

That sub really makes a difference whether watching HDTV or a DVD.

Thanks again all!

jk3