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Discussion Starter · #1 ·
In order to maximize the distance between the rear speakers and the seats, I'm going to take advantage of the flexibility I have right now to make "recessed" openings out of the drywall for my rear speakers in a 7.1 setup.


I'm going to follow the 1.2 rule (thanks sanjay!) for the spacing between them (1.2x distance from listeners) and have them 2-3 feet above ear level.


There are 2 issues I'm worried about right now:

1. the size of the opening. The speakers that are going in right now are Athena AS-B1s. Their dimensions are (WxHxD) 18cm x 35cm x 24.1cm or 7" x 13 3/4" x 9 1/2". While it'd be nice to make it a perfectly flush fit, I'd like to allow some flexibility for upgrading speakers in the future. This may be a little vague but - how big do quality rear speakers get these days?


2. as you may or may not know - the AS-B1s are rear-ported. I know it usually isn't recommended to mount them "in-wall" like I plan to... What can I do to minimize the negative implications of this? Should I allow an extra 3" of depth behind the speaker to let it breathe? (or deeper?) Should the sides of the speaker be stuffed air-tight so that the front of the speaker is totally isolated from the rear port? Should I poke a hole in the back of the drywall to let the rear port breathe into another room? I'm totally stumped on this one - but I have the freedom to do pretty much anything right now, as long as I figure it out within the next couple of days.


3. I know I said 2 but thought I might as well throw in this one for the nit-picky - they say to put rear speakers 2-3 feet above ears... Should this be measured to the bottom of the speaker enclosure? Or the tweeter?


Long post... Greatly appreciate any advice!!!
 

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1. Murphys law dictates that whatever dimentions you make the cavity the speakers you'll want to up grade too later on won't fit it :) , you may as well do a flush fit.


2. Stuff the port with dense foam or similar, this will typically give the speakers a critically damped sealed alignment, which will be perfectly fine for surround use, and won't harm the drivers. The output you loose from the port you'll mostly gain back by flush mounting (no baffle step)


3. measure from a point in-between the woofer and the tweeter.
 

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Discussion Starter · #3 ·
what about behind the speakers? how much room should i allow to breathe? or should i vent into the next room? :confused:
 

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If you stuff the vents of the speakers you don't need to allow any breathing room since they'll effectively be sealed, you then only need to make the cavity as deep as the speaker is (with a little wiggle room to allow for wiring ect)
 

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As a preview you can take a hand towel roll it up and plug the port. You should notice a drop in the bass but for rears it may not be improtant. If the result really sucks you may want to think about much larger recessess and breathing room around the back of the speaker.
 

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You can "stuff" the ports and you can mount in a recess; however, the speaker you have now will NOT be the same speaker once you've blocked the port and 2pi loaded the speaker. The resultant timbre change in the speaker may very well turn out to be a horrid experience. I'd try it first before going head long into some thing like this. You could be very much better off sucking it up and getting different speakers for the sides and rear.
 

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Discussion Starter · #7 ·
Dennis - what if I left about 2.5" inches of breathing room behind the speaker, as well as an 1/8th or so on all the sides?


Would that have a less adverse effect on the sound?
 

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Quote:
Originally Posted by Dennis Erskine
Nope.
Hey, you can't answer two opposite questions with a nope!

Clay
 

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Leaving breathing room behind and to the sides of the speaker actually creates a port extension which will definitely change the tuning of the enclosure. Whether the undesirable effects are enough for you to worry about is totally up to you. I would agree that if you must recess these, block off the port and create a sealed enclosure. They won't sound the same, but perhaps they won't sound bad either.
 
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