SpikeJr,
That JL setup looks nice, but a 6.5 can only make so much low end without a substantial enclosure. My Boxster has the factory woofers in the doors, and they actually sound pretty good, but I'm thinking I'll just bandpass them up at like 120 Hz once I have a sub so they can sing in their more optimal range. I've read a bunch of other sub threads here and elsewhere including one that talked about a custom fiberglass enclosure behind the passenger seat, but there were never any pictures of that one. Some legroom will be lost, but my goal is to keep it to a few inches, so for short trips even I at 5'10" can tolerate it while letting my 5'6" wife pilot (however she usually isn't driving ;o)). It seems that any speaker-well design is going to get kicked with my size 12s. My idea for porting under the seat wouldn't be physical tubes under the seat, just that the port(s) would fire there. With an enclosure this small (~.5 cu ft) and cone this big, ports probably won't actually be a benefit over sealed. Any sub enclosure in the cockpit is tight, which is why I'm thinking removable would be ideal- no passenger=sub, passenger=no sub. I'm tempted to try fiberglass so it is more form-fit, but I don't have much experience with it, and it can be kind of a mess.
JayG,
There are some prefab under seat subs out there which might work if you can keep the passenger from lowering the seat onto them like SpikeJr mentioned- it's really shallow and narrow under there.
Running a woofer of any size without an enclosure would result in nearly 100% wave cancellation from the front to the rear. You could still probably feel it a little bit, you would probably only hear physical noise from the cone/surround travel if there is no baffling or box to cancel or line up the phase of the back of the speaker with the front. You'd almost definitely be better of with a bass shaker like:
http://986forum.com/forums/diy-project-guides/28126-sound-system-upgrade-plus-subwoofer-answer.html
Still waiting for the sub to arrive...
Hybrid Mode
