Best way to decrease the internal volume of a sealed speaker?


I have a very fine sealed 0.75 cu foot cabinet that I would like to reduce the internal volume to about to about 0.45-0.65 cu feet. There is limited space to add things like bricks, pavers etc inside.
I am thinking of using some plastic containers with lids glued to the inside cabinet. Should they be filled with sand?

ozzy


128x128ozzy
Oz, FlexSeal does contain 'aliphatic petroleum solvent' & 'liquified petroleum gas'...so save it for your roof or 'cutting/repairing boats' ( right, sure...)....;)

Black Hole does sound like a win...I'd coat the interior with a white latex first, for the seal & dust issue and it'll ensure the BH will stick 'n stay...

Your calcs are correct...*G*  I had a thought as to how you might 'dial' the cabs in for your SSRs', since the difference between 173 & 519 cu.in. is rather large.  It would entail a bit of swapping the face panel on & off, but the cab does have the hardware that would make it less painless...

A typical 4x4 from Home Despot...nominal 3 5/8" sq. = 13.14 sq.in.

173 / 13.14 = 13 1/8"  for .65 cu.ft.
519 / 13.14 = 39 1/2"  for .45 cu.ft.

One 4x4 @ 8' ought to be enough for both.

Divide those lengths to fit within, add/subtract until you like what you hear.  Duplicate for cab #2.  Glue down, paint, apply BH, final assembly.

Crack a cold one and enjoy the fruit of labor, etc.

Ought to beat mucking about with foam...'interior aesthetics' are up to you. ;)  That interior bracing panel shown in the PE pics makes doing something on the back panel to break standing waves front/rear (one of my pet peeves..) difficult to address....but some of my projects go off the deep end with such...

Good luck...*S*


asvjerry,

Thank you so much for your information. I am now leaning towards the higher volume 0.65 internals. This means I only need to reduce the inside by 173.

I guess the only issue I have with using 4x4’s is that they would probably need to be just glued at the top inside. And then the  cabinet with the 4X4’s glued would be placed on its back to finish the speaker / front baffle install until it can be uprighted again to rest on the stand.
So, I am not sure how well a glued 4x4(s) would stay stationary during that movement. Does liquid nails work that great?

ozzy
Oz, I'm not a big fan of Liquid Nails...I'd suggest a tube of 'fast set' silicone caulk, applied 'bout the diameter of toothpaste... Somewhat 'stinky' (acetic acid, a.k.a. vinegar...*L* Fades away soon enough...) but not toxic to you or electronics....

Sets up in about an hour...since the 4x4 pieces are small, there shouldn't be any issues.  You could cut the 4x4 into smaller pieces (2, 3, etc.) to make it less of a 'hunk', and distribute them within the cab.  Smaller will be less likely to come loose, regardless of how loud you push them... ;)

BTW, re the 4x4....try to select one that's as 'dry' as possible.  If they're all 'wet', let it sit for awhile either in the sun or indoors in a warm space.  4x4s' are typically pressure treated for exterior use and can be moist.  It's a copper-based solution; again, safe to you and gadgets.  If the wood's dry(er), the silicone will adhere better....

Have fun, mind your fingers around the saws....;)


Ozzy,

1 gallon displaces 241 cubic inches. So a gallon of Cascade when cured should shrink down to the volume you require..you would need a gallon for each box..They would be well sealed and more rigid. Tom 
Why not simply get a quantum device from Geoff or an air compliance device from Bybee?

Why bother fiddling with foam, glue and other physical stuff and having to open up the speaker.

Simply employ one of these quantum mechanical devces to warp the space time dimensions of your speakers or change the actual behaviour of air compliance of your entire room to have the same desired effect.

Engineering by length, volume and acoustic properties is so old school.

Alternatively your speaker wires can be useful in changing speaker response as effectively as any physical change. A change of 1 meter in cable length is just like a volume change of 1 liter.

Alternatively, your thanksgiving turkey is perfect for stuffing a speaker but may work even better if placed on your head.

Here is a DIY instruction video

https://m.youtube.com/watch?v=E_Rabq4muu0