Hi all: <BR> <BR>I want my sub to have alot of clean punch and less rumble. I heard that a sealed box is better for punch than a ported box, so I've got a sealed box. <BR> <BR>Now should I omit any baffle material in the sealed box, or add alot of baffle material to the box, or does it matter?

stuff it with fiberglass insulation. It allows you to keep the air space but break it up. I usually spray adhesive the inside walls of the sub box and stick up some insulation. That works fine.

sealed will help. If you've never had a sealed box, it may be all you need. I've never stuffed a box with anything. However, I'm about to build a 12" enclosure and was doing some research online. Some guy that builds home theater speaker towers spent way too much time researching the sound dynamics and built a lot of baffles into his towers. Supposedly, if you dampen the resonance in the back of the speaker it allows for a cleaner transfer through the speaker...? i'll try to find it.

I hate working with fiberglass insulation, your voice coils may hate it too. Use dacron fiberfill from an old couch pillow or from the fabric store (or from a plane pillow). If the box is correctly sized fill it about 50% with fluffed stuffing, if it undersized fill it all the way with fluffed stuffing. <BR> <BR>The main purpose of the stuffing is to keep the wave coming off the back of the speaker from hitting the back wall of your box, bouncing back and hitting the sub cone causing distortion. Sealed box keeps back wave from canceling front wave. Ported box allows back wave to be tuned to align and reinforce front wave (hard to do correctly).

Mike: <BR> <BR>As usual, you've done a great job of explaining the complicated in plain english... and saved me again.

a lot will depend on how much box volume the woofer requires.... <BR> <BR>if more, than stuffing will slow the back wave down and the woofer will perform like it is in a larger box... <BR> <BR>sealed boxes sound better at low volume while ported can take more power with less distortion. i have both and it really depends on the enviorment. <BR> <BR>if you do use stuffing, make sure each side gets the same exact amount (gram weight)

The stuffing actually creates a thermodynamic phenomenon which heats the air slightly and "tricks" the woofer into reacting as if the box were a bit larger in volume. If you're looking to damp the internal reflections inside the box (not as necessary on a sealed box since the wavelengths are between 11 and 56 feet long) then a more dense material like carpet underlay in conjunction with a small amount of packed insulation is a better choice. On a ported enclosure the underlay works very well to keep mid frequency mechanical noises from coming out of the port. By the way, many ported box designs can give you very smooth, punchy bass if they are designed properly, the enclosure will just be larger than the sealed one. Ported will give a lot more output in a boat though.

Should I stuff the 6.5 inch speaker cans that I am making???

I think I over stuffed it and it doesn't have enough air space now. I'm going to take some of that poly out.