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Speakers VERY close to wall - Cork board useful?

Hi there,

I have a set of Klipsch RP-5's, that have a built in powered sub, and a rear facing port on the bottom of each tower. I have them in a small room (15'x13') with about 6' of separation. Considering the small room dimensions I have them pushed up against the wall because otherwise they'd be in the way. They are at least at a slight angle, but the port for the sub is still only about 4" off the wall. 

Would putting a square of cork board on the wall directly behind the port, cut out so its slightly larger than the port, make any positive difference compared to an ordinary sheetrock wall?  (The cork comes in a roll, so it is maybe 1/8" thick)

Any thoughts, additional suggestions on other common house-hold materials/geometry of cut/ etc, or comments would be appreciated! (other than "move the speakers away from wall" bc unfortunately that's not an option in this room)

:)
thanks!!!
hockey4496
williewonka
3,082 posts
 
Hockey4496 - unfortunately cork is not the solution for this problem.

You would achieve better results from carpet or rug as suggested by Czairvey. Underlay under the carpet will also help.

An option that I have tried with great success it to redirect the direction of airflow from the port by installing a Perko Chromalex Cowl Vent over the port.

http://www.jamestowndistributors.com/userportal/show_product.do?pid=11143&familyName=Perko+Chrom...

It worked very well in my case and made the speakers perform so much better across the entire bottom end - almost eliminating the muddiness and booming I had before..

Once installed, moving the speakers out just a couple more inches will improve things further.

Since you have carpet on the floor I would try pointing the vent downwards first.

Crazy Option ??? - maybe, but it worked

And - it's cheaper than new speakers :-)
sbank's avatar
sbank
3,379 posts
 
Clever move, Willy. Sort of a "transmission line band aid". Cheers,
Spencer
hockey4496 OP
104 posts
 
Clever idea, I am give that a try. Thanks!
audiokinesis
2,747 posts
 

Willy Wonka’s cowl increased the effective port length and lowered the tuning frequency, which is the direction you want to go to compensate for the increased boundary reinforcement from placement near the wall.  I incorporate variable port tuning into most of my designs to deal with similar situations. 

It is also possible to lower the tuning frequency by decreasing the port’s cross-sectional area throughout its length, perhaps by inserting a smaller-diameter tube into the port. The smaller-diameter tube would be wrapped with tape as needed to get a good friction fit.

hockey4496 OP
104 posts
 
Williewonka - 
did you just slide the vent you bought into the speaker port? Or did you attach it in a particular way (modify speaker port, wrap tape to get correct diameter, etc.) I have some curved pvc tubing in the garage that may be about the right size that's could try without having to spend anymore $$ if it will work the same

thanks!
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