Cavity options for in-walls?

[lario]

I'm in the process of setting up 5 in-wall speakers (open backs) in a 11x14 sized room. The centre and front left/right are positioned on an exterior wall and have the benefit of insulation (in the wall) to reduce noise bleeding, etc. The rear positions however do not have insulation between the studs and I fear sound reproduction may be impacted. Behind one of the rears is just the 'under the stairs' space so I don't even have a backing to even stuff some insulation and/or foam in there. Anyone have an idea? The only think I can think of is perhaps purchasing some foam that I can cut out and stick on the back of the speakers (say around the magnet?) so that it stays in place and offers some element of insulation. Thoughts?

 

[ack_bak]

I'm in the process of setting up 5 in-wall speakers (open backs) in a 11x14 sized room. The centre and front left/right are positioned on an exterior wall and have the benefit of insulation (in the wall) to reduce noise bleeding, etc. The rear positions however do not have insulation between the studs and I fear sound reproduction may be impacted. Behind one of the rears is just the 'under the stairs' space so I don't even have a backing to even stuff some insulation and/or foam in there. Anyone have an idea? The only think I can think of is perhaps purchasing some foam that I can cut out and stick on the back of the speakers (say around the magnet?) so that it stays in place and offers some element of insulation. Thoughts?

I would consult the manufacturer of the speaker. They are designed to be open baffle for a reason and you would want to be careful applying any material to the speaker. Any option to return the rear speakers and buy in-walls with enclosures? Or go with some surrounds that are mounted to the wall?