My other vehicle is a 2005 Xterra with the OEM Rockford Fosgate stereo option. It comes with an 8" sub, mounted under the driver's seat in a plastic enclosure. The system has been "ok" but am itching to upgrade it. Problem is, I use the rear hatch space--alot--and flip my rear seats forward often also. I want a sub but don't want to have to remove it from the rear hatch area every other day. I couldn't find any other acceptable location other than the factory location; under the drivers seat.

I was thinking of either modifying the factory enclosure to accept this sub because the box is very, very short--and this sub only requires a 3" mounting depth:



My question is, as long as I can stretch the box out sideways to achieve optimum box volume, will there be a difference in sound quality or spl between a skinny box with 0.5ft^3 of space vs. a cubic box with 0.5ft^3 of space?

 

can't answer your question, but I recently stumbled across
another shallow sub:
http://www.blaupunkt.com/us/loudspeakers_121.asp
I know nothing more than what the website says.

 

The shape of the box doesn't matter as long as you have the correct volume. However, I have my doubts about a sub with that shallow of a mounting depth really sounding all that great. Not to say it doesn't but I'd certainly suggest hearing one before purchasing it.

I know you said you you're opposed to putting a sub in the back that would have to be removed...but as an alternative, here's what I did in my wifes Rav4.

I installed a powered Bazooka sub tube, and used a Stinger quick disconnect for the power, which enables it to be pulled out really quick and easy.



Just unplug that, the rca's and the turn on lead...and it's out in about 15 seconds. Plus the thing is really rugged, it only has to be pulled out if we're moving something huge. Most stuff we can just throw right on top of it. And that setup sounds fantastic! My original intent was just to add a little more bass to it...and I was just floored by how good it sounded. And all the system consists of is an aftermarket head unit, and the Bazooka.

 

I believe the Fosgate system in the Xterra uses very low impedance speakers (1/2 - 1 ohm?) in order to achieve decent power without resorting an overly complicated/expensive amp design. That said, connecting a more "normal" impedance woofer to the factory amp won't allow the amp to make much power. You may actually end up with less bass than what the factory system delivers.

IF you can build an enclosure with sufficient volume for the Pioneer woofer to work under the seat, you will need to drive it with a new amplifier. You then have amplifier mounting considerations too.

You could have someone fab a custom shaped enclosure to fit in one of the rear sides that wouldn't impede on floor space then remove the factory woofer and put an amp in its place under the driver seat. Or you could look for more simple alternatives like the Bazooka tube Dcon67 mentioned. The good thing about the Bazooka or similar woofers is that it can move to a new/different car someday. Look for something with a separate bass level control.

Good luck.

 

I had some of the Blaupunkt drivers and the "mounting depth" was a little different than advertised because Blaupunkt didn't count the part that protruded from the front. So in an under-seat design they took a lot more depth than the dimensions suggested.

You might get a decent amount of bass by upgrading (or adding to) the drivers in the doors. Generally doors are not the best place to put bass drivers but yours probably have a lot of volume and you might be able to fit a 7" or 8" woofer in each door, and a pair of good 8's and a separate amp could easily out-perform the under-seat sub.

To get a lot of bass you have to move a lot of air and that means either large surface area (speaker diameter) or a lot of excursion (the amount the cone moves in & out). A speaker's maximum excursion is called "Xmax" so it's a good paramater to look at when choosing a speaker you want to use for a bass driver. Anything with less than 6mm Xmax should be ignored (IMO) for decent sub use.

 

Thanks for the replies.

Listener, you are correct; the factory sub is a dvc model running the amp at a 2 ohm load. However, when I put in the new sub a new amp is a must. There is plenty of room under the passenger seat; that's where the factory amp is.

Modifry, I was very seriously considering your suggestion, to install bass drivers in the doors. However, I felt this involved much more custom work and introduces the possibility of more rattles than expanding on the sub-under-seat concept. Someone else pointed out the Blaupunkt woofer; and it looks pretty cool but has less range and power handling than the Pioneer. So we'll see.