I built a 2x12 speaker cabinet for my guitar amp today. It's unfinished at the time and I was thinking that instead of covering it with tolex or lacquered tweed that I'd spray or roll it with textured bed liner. I imagine that would be much more durable.

Is this a good idea or a terrible idea? Can you recommend a brand?

I designed it with Fusion 360 to get the dimensions correct:


And here's how it turned out:

This message has been edited. Last edited by: mark123,

Is that dovetailed? Nice work! I would think if you're transporting it, it would make it more durable. I wouldn't think it would be worse than wrapping it in carpet.

quote:

Originally posted by IntrepidTraveler:
Is that dovetailed? Nice work! I would think if you're transporting it, it would make it more durable. I wouldn't think it would be worse than wrapping it in carpet.

It's not dovetail, it's finger joint. I figured that since it's not going to be visible, dovetails add complexity without adding strength.

I would suggest using this product:

link

I use to line the subwoofer boxes with this stuff and it made the cabinet absolutely non-resonating acoustically. Extremely easy to use and cut after it dries. Inexpensive, too. YMMV

quote:

Originally posted by synthplayer:
I would suggest using this product:

link

I use to line the subwoofer boxes with this stuff and it made the cabinet absolutely non-resonating acoustically. Extremely easy to use and cut after it dries. Inexpensive, too. YMMV

Do you cover the entire inside with it?

What did you do for the outside?

Looks real good. We sure do have some talented folks around here.

I would look into Raptor Liner likely the easiet and best DIY bed liner. Can do any color under the sun fairly easily.

LizardSkin sound control may be an idea too.
http://m.lizardskin.com/sound-control-insulation.html

quote:

Originally posted by Black92LX:
Looks real good. We sure do have some talented folks around here.

I would look into Raptor Liner likely the easiet and best DIY bed liner. Can do any color under the sun fairly easily.

LizardSkin sound control may be an idea too.
http://m.lizardskin.com/sound-control-insulation.html

Thanks! The raptor liner looks nice. I'll check into it.

quote:

Originally posted by mark123:

quote:

Originally posted by synthplayer:
I would suggest using this product:

link

I use to line the subwoofer boxes with this stuff and it made the cabinet absolutely non-resonating acoustically. Extremely easy to use and cut after it dries. Inexpensive, too. YMMV

Do you cover the entire inside with it?

What did you do for the outside?

Guitar Center sells a "carpet" like material that is intended for such purpose. I don't have your wood working skills - I never built a cabinet. We would purchase subwoofer cabs for our band, and I would take them apart and spray the inside of the cab with foam. I'd cover every surface with it, with a bit more concentration on the corners.

How are you doing the finger joints? For small boxes I use a blade kerf width tablesaw jig. I have a piece of phenolic laminate machined for 1/4” fingers, I need to build into a router jig. Before I retire from where I work, I hope to get a similar piece machined for 1/2” fingers.

quote:

Originally posted by BGULL:
How are you doing the finger joints? For small boxes I use a blade kerf width tablesaw jig. I have a piece of phenolic laminate machined for 1/4” fingers, I need to build into a router jig. Before I retire from where I work, I hope to get a similar piece machined for 1/2” fingers.

I use a finger joint jig and a dado set. At first, I made the jig but found that the Incra ibox really lets you dial in the accuracy. And it's repeatable results.

I’ve never built a guitar can but I’ve built countless subwoofer cabs, mostly for car audio but also a handful for recording studios and live sound reinforcement (think outdoor concerts). Those ones were particularly beastly.

Do you plan on closing the box? I know some cabinets for guitar leave the back open. I’d at least suggest a half piece in the back to help increase the rigidity. I’d also consider adding an internal brace system on the face. Big panels flex and flex is bad for sound and bad for longevity.

That being said, a guitar can won’t have anywhere near the stresses of a subwoofer cab for a high power system, so it’d probably be ok... I always skewed towards significant overbuilding but the truth is the drivers aren’t even in the same ballpark... very different applications.

The expanding foam is a good thought and has benefits, but a couple of concerns come to mind. If the whole inside is coated with the stuff it WILL noticeably affect the internal volume. This is a vitally important concern in sub boxes but I’m sure much les vital in guitar cabs.

The other concern is off gassing which may or may not be a concern for some of thensoft parts found on a speaker... proper airing out would solve that.

And if you don’t plan on closing the back then neither the change in volume of the possible off gassing is a concern.

As far as the original question.... I’d do a speaker carpet. I once finished a pair of giant towers for my home theatre in roll on bedliner... it was terrible. A professional job would probably produce better results but I ended up scraping and sanding that junk off and refinished in a paint.

I'm definitely not going to use carpet. I had a 1x12 speaker cabinet that was factory carpeted. It's gross, cannot be cleaned or dehaired.

Last one I did I glued a textured black vinyl product over the exterior to match all the Peavy crap I was using at the time.

I would have used MDF over plywood.
Makes for better acoustics.
Covering the outside is purely cosmetic and should be done as desired.

quote:

Originally posted by mark123:
I'm definitely not going to use carpet. I had a 1x12 speaker cabinet that was factory carpeted. It's gross, cannot be cleaned or dehaired.

Agreed. They don't call it rat-fur for nothing. It gets nasty.

quote:

Originally posted by vinnybass:
Agreed. They don't call it rat-fur for nothing. It gets nasty.

I never heard that term but it fits! Hahaha!

I have a pair of Jensen C12Rs that I got out of an old Wurlitzer organ that someone gave me for free. I stuck them in and closed the back and it sounds great! I'm stoked.

Bedliner is an excellent idea, and a very durable finish. I can't recommend a DIY brand, but I'd suggest talking to a shop that does actual bedliners. I imagine if you prep it yourself, ie. sanded, cleaned, whatever they recommend, they wouldn't charge more than $50-100 to spray it. Maybe even if they prepped it as well.

quote:

Originally posted by mark123:

quote:

Originally posted by Black92LX:
Looks real good. We sure do have some talented folks around here.

I would look into Raptor Liner likely the easiet and best DIY bed liner. Can do any color under the sun fairly easily.

LizardSkin sound control may be an idea too.
http://m.lizardskin.com/sound-control-insulation.html

Thanks! The raptor liner looks nice. I'll check into it.

From what I've read, the Raptor Liner seems to be glossy and I don't think that will be ideal.

I got the handles installed and sprayed the speaker baffle flat black today. I'm happy with the results so far.

my only concern about bedliner... if it separated from the substrate over time, or cracked, it might rattle.