Backer box for in wall speakers

I apologize if this is not the proper section to post this. I posted it in here and the diy thread. I feel really dumb but will ask. I have a new construction house that's being built. I will have 4 in wall speakers and 4 ceiling speakers for surround and atmos. Does anyone on here build backer boxes on the side? I would obviously pay for material and labor if anyone does this on the side. I've emailed several companies, mostly with no response including Polk for backer box dimensions. I have 4 Polk RT 65 in wall speakers. 4 Polk RT 70 ceiling speakers. If anyone does this or could help me with the size I'd need I could hopefully find someone to build them. Thank you


  • SeleniumFalcon
    SeleniumFalcon Posts: 3,383
    In general terms the majority of Polk's in-wall and in-ceiling speakers don't require a specific volume of air behind the speaker for best performance. They are what is referred to as "infinite baffle" type speakers meaning all that has to happen is the rear moving sound wave needs to be isolated from the front sound wave. However, some of Polk's speakers can benefit from a specific volume of air behind the speaker to smooth and extend the bass performance. It all depends upon the specifics of the speaker's design parameters. I've asked a friend at Polk if your RT Series can benefit this way. I'll post his response as soon as I have it.
  • SeleniumFalcon
    SeleniumFalcon Posts: 3,383
    edited May 2021
    The speakers can be used with a 1.2 cubic foot sealed enclosure.
    It's easiest to simply put a piece of wood above and below the space between the joists to create the sealed enclosure. For example let's say the depth of the joist is 3" and the distance between joists is 10". If two pieces of wood are placed horizontally about 7" apart this will create the 1.2 cubic foot volume behind the speaker.
  • randbrus84
    randbrus84 Posts: 4
    Thank you very much for time and help