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
theaudiotweak,

Thanks. First I’m going to try the Styrofoam. I have a piece that should work out fine cubic inches wise (177.42).
I will be gluing this underneath of the inside top. I just hope it doesn’t come loose or rattle.

Shadorne,

Too much holiday cheer?


ozzy
Sorry for the late reply.. the expandable foam will dry with a smooth surface, unless you mess with it. It will be flexible, though, so take Erik's advice into account. I'm not sure how flexible materials would effectively increase the internal volume, but Erik doesn't tend to talk out his butt and has much experience building speakers.

That said, nothing wrong with experimenting.

If you do use 2x4's, considering using blue tack to hold them in place until you're happy with the sound. Then, if the cabinets are unpainted MDF on the inside, consider wood glue. It is very strong when gluing wood together (duh) and would not be flexible like silicone, which could add too much damping. Or maybe you need the extra damping of the silicone.. I suppose you could start with silicone and, if it's over damped, cut it out and use wood glue.

As I see it, you want to take out between 0.10 to 0.30 cu.ft.

Use a cu.ft. to cu.in. calculator to convert. I would use 2x4s.

Start out with the smaller piece of wood then adding more blocks until you get your desired sound. Use double sided foam tape (3M @ Home Depot) that way you can add or remove the blocks.

I'v built quite a few speakers an using the calculator helps greatly in figuring out interior Cu.Ft. or Inches.

Hope this helps.

Ozzy

Seal the sawdust and glue with something...varnish the inside a couple of coats or so.Tom