In article 3FFBCEFD.3030108@usefirstinitialandlastnameATerol s.com,
Simon Juncal
wrote:

okay I've got the center console of a Jeep to use as a sub enclosure...
I've got an 8" JL 8W0 cocked at an angle roughly 45 degrees facing the
lid of the console. The inside dimensions (aprroximate due to curves in
the bottom) are 19" front to back, 8 3/4' wide by 7 3/4" deep. Not too
drastically off from JL's recommendations. However the sub will not be
firing out into the listening space, so I'm wondering what would be the
best way to compensate for that and the fact that the enclosure is
somewhat smaller than recommended and that the sub will be totally
enclosed. I've got a 2 1/2" PVC vent that I can cut down (JL recommends
2 1/2" by 12.4 but that's in a bigger box). So my question is with a
completely enclosed sub; should I use polyfill and a short vent, and
where along the length of the console should I mount the sub (at one end
or the other or in the middle?). Also should I face the sub towards the
vent or away from it?

If it sounds like crap I guess I'll end up getting a box and let it bang
around, but there's no good place for a sub enclosure in a jeep, and
hidden away inside the console is just too elegant to not at least try.

I wouldn't use a port at all. It's asking for trouble when the box is
undersized and conditions aren't perfect. Most likely it will leak out
the low-end and buzz rather than create a mild resonation to help the
lowest frequencies. It will sound really bad if it buzzes badly enough
to make your CD player skip on certain notes.

The only kind of port likely to help would be a long and fat pipe that
adds to the box volume. A special speaker calculator is needed for
ports that are large compared to the enclosure. I've seen them before
online but don't remember where. It's probably more trouble than it's
worth, especially when it comes to routing a giant port under the dash.

Polyfill helps a sealed enclosure.

BTW, I do hope you're talking about an inclosure installed inside the
interior panels. The plastic panels alone won't hold much sound
pressure, maybe only 35W average without breaking or hissing from air
leaks. At least line it with fiberglass inside to stiffen it and form
an airtight seal.