Mounting subs in existing metal dead space

[rogermija]

In my RV there is an unused cavity just below the kitchen floor but exposed after removing a sheet metal plate in the cab area. The cavity is approximately 8"h x 5"d x 30" w. There is room for one or two 6.5" woofers. Being structural metal, will the cavity work as a sound box? If needed, there is room for a tube port through the floor. Will this cavity work and, if so, what parameters should I consider? Thank you.

 

[Jimi77]

Metal resonates too much for a subwoofer enclosure. I'd fiberglass that space. You have ~.75cuft to work with, which is a decent amount of space for two 8s sealed or single 8 ported.

 

[rogermija]

Metal resonates too much for a subwoofer enclosure. I'd fiberglass that space. You have ~.75cuft to work with, which is a decent amount of space for two 8s sealed or single 8 ported.

Thank you for the response. Glassing would be a challenge. Would self adhesive sound absorbing rubber or some thing similar work?

 

[Jimi77]

Thank you for the response. Glassing would be a challenge. Would self adhesive sound absorbing rubber or some thing similar work?

Sound deadeners won't cut the mustard IMHO. Why can't it be glassed?

If you're just trying to throw something in and keep it as easy and simple as possible, then I'd sound deaden the area, go sealed and use a high quality acoustic damper like Acousta-Stuf. You'll probably end up with ringing. You can dampen the front side of the cone to help control the ringing, but that will cost you efficiency and potentially output depending on the sub.

 

[rogermija]

Thanks again. The metal is part of the chassis frame except for a portion of the sheet metal which has three stiffeners along the 30" portion. The front of the space is currently enclosed with sheet metal accessible from the rv cab area. I plan on removing an 8" x 15" section. Glassing may be a challenge through that small opening especially in the far corners. I'll check out Acousta-Stuf.

 

[huberoy123]

In my RV there is an unused cavity just below the kitchen floor but exposed after removing a sheet metal plate in the cab area. The cavity is approximately 8"h x 5"d x 30" w. There is room for one or two 6.5" woofers. Being structural metal, will the cavity work as a sound box? If needed, there is room for a tube port through the floor. Will this cavity work and, if so, what parameters should I consider? Thank you.

A photo of the area would be helpful.

 

[rogermija]

A photo of the area would be helpful.

I have not cut the access hole yet. But I will get a snap for reference. In the meantime, how does Acousta-stu compare to acoustic foam for this application? Thank you.

 

[Jimi77]

I have not cut the access hole yet. But I will get a snap for reference. In the meantime, how does Acousta-stu compare to acoustic foam for this application? Thank you.

Acousta stuff is more to give the space the illusion of more airspace but also damps sound. Acoustic foam just damps the sound. Acoustic foam could be a good option too.

 

[SlugButter]

fill the cracks with Great Stuff foam. trim the excess off with a razor blade after it dries. Use spray on bedliner to thoroughly cover the inside. Multiple coats. Use a 3/4 inch or 1 inch thick wooden baffle for the subs and make sure it’s screwed down sealed well.

 

[SHO'NUFF]

fill the cracks with Great Stuff foam. trim the excess off with a razor blade after it dries. Use spray on bedliner to thoroughly cover the inside. Multiple coats. Use a 3/4 inch or 1 inch thick wooden baffle for the subs and make sure it’s screwed down sealed well.

Yeah, maybe stick some deadener on the bare metal before you spray the bedliner.

How much power are we talking?

 

[rogermija]

A photo of the area would be helpful.

I tried to send a snap of the area but the clipboard would not paste to this site. Do you have suggestion on sending pix?

 

[rogermija]

Thanks. Area for sub mounting is approximately 15" wide and 8" high. There is a 1" vertical stiffener brace half way across.

 

[AnthonyO]

Why not just build a enclosure per specs of the floor with MDF, Birch, whatever? And be done with it.

 

[huberoy123]

I like the idea of building a box and dropping it in.