does the subwoofer have a vented pole piece?

 

I would say yes.

Ultimo SC 12
http://www.morelhifi.com/support/pdf/mobile/Ultimo Manual.pdf

 

I have always went by the rule of thumb. The min. allowable dimension from the vented pole piece to an enclosure wall or port is equal to the diameter of the vented pole piece.

 

^^^This is what I have always gone by.

 

Hahaha cheater!

Well done I will look into that.

 

Cheating?! Lol I like to think of it as doing what ya gotta do.
You know all too well there isn't crap for extra room under, or behind those seats.

I used 3" steel C channel. Had it cut in 2-3" sections, then drilled them to match the mounting locations of the seats.
Then You just have to source hardware to mount the seats.

It was a PITA getting it to all line up, but worth it. Opened up a lot more options for enclosures.

 

Great idea I like the way you think!

One thing though, is it skirt-friendly?

I think I'll just go trade the Ultimo SC for a JL 13TW5-3 shallow mount and be done with it.

Thanks for the advice and info on the seat lift. I will consider that mod if this JL doesn't do it for me.

 

Lol I don't see why not, but I only let the kids back there anymore.

Kinda a tight fit for the oldest though... He's 15 and 6'6". Lol

 

The best option as far as enclosure size and mounting depth is the Polk MM1240. Are these any good for sql?

They're cheap and can take some power and they're only 4.7" deep. So I would have nearly 2" clearance. That should be enough, right?

 

2 inches will be plenty of room