Will be going into a 03 Civic sedan, and powered by a Ultimate T3-1000D (around 2000W RMS).

15" BL would have cooling, flatwind, and enclosure would be the following:

3.1 ft^3, 33hz, 43.5 in^2 of port

12" BTL would have cooling, HiXmCoil, and enclosure would be the following:

2.5 ft^3, 33hz, 37 in^2 of port

I am wondering if the HiXmCoil would make up for the loss of surface area going from a 15 to a 12? Should I squeeze the 15 into a smaller box or give the 12 lots of room to breathe? I want to move as much air as possible but in a daily driver situation. Thanks in advance for responses and suggestions!

i would think the 12 would move as much air as the 15. my 12 moves a ton of air. and then later on down the line if oyu want to throw more power at the sub you can do that with the BTL not so much the bl

i would think the 12 would move as much air as the 15. my 12 moves a ton of air. and then later on down the line if oyu want to throw more power at the sub you can do that with the BTL not so much the bl

I think i see what you are trying to say but no, due to surface area, the 15BL will move more air. However, if the BL is in a bad enclosure, and the BTL is in a proper enclosure, the BTL may very well be louder. Just my $.02

Both enclosures are within Fi's recommendations. However, the 15 would be in a relatively small box (3ft^3, with 12" port per cubic ft) and the 12 would be in a relatively larger enclosure (2.5, with 15" port per cubic ft). Both within recommended ranges but the 12" box is much more optimal. I suppose the question is more about box size than the drivers themselves. Which would be better 15 in a smaller box or a 12 in an optimal one?

Both enclosures are within Fi's recommendations. However, the 15 would be in a relatively small box (3ft^3, with 12" port per cubic ft) and the 12 would be in a relatively larger enclosure (2.5, with 15" port per cubic ft). Both within recommended ranges but the 12" box is much more optimal. I suppose the question is more about box size than the drivers themselves. Which would be better 15 in a smaller box or a 12 in an optimal one?

Optimal is best.

and later on down the road if you go with the 12 you wont have to upgrade the sub to upgrade the spl level. just get a bigger amp. the btl can take alot more than rated.

I used to run a Q series 15", and I would like to match or exceed the output with my new purchase. The Q was presenting a 4ohm load on my amp so I by switching to dual 1ohm I hope to get close to 800W RMS from my amp. (the spec's show 2700Wrms into a 2ohm load but I am skeptical....) In an optimal enclosure can I expect this kind of output from a 12"BTL with the aforementioned options? Thanks for the feedback!

I used to run a Q series 15", and I would like to match or exceed the output with my new purchase. The Q was presenting a 4ohm load on my amp so I by switching to dual 1ohm I hope to get close to 800W RMS from my amp. (the spec's show 2700Wrms into a 2ohm load but I am skeptical....) In an optimal enclosure can I expect this kind of output from a 12"BTL with the aforementioned options? Thanks for the feedback!

What didn't you like about the Q?

I love my BL 15 its loud and it moves a lot of air.

What didn't you like about the Q?

Nothing! I loved the Q, but it took too much abuse. Tinsel Leads broke after a few years. I have patched up the driver a couple times but it has just been too far damaged. I also just realized that the box it is in right now is too small for it, (Bad design error on my part) which I am sure has aided in its depreciation. The previous box it was in was fantastic but my new ride didn't have the trunk space for it. I really gave that speaker a beat down, but I loved it which is why I want another Fi Audio subwoofer.

The more I think about it the more I am leaning toward the BTL fully loaded. It will be in a proper enclosure that will fit in my trunk a hell of a lot easier. It should handle any power that I can throw at it even if I upgrade my amp in the future. My biggest concern is that with that drop in cone surface area it won't be able to create that breathtaking low end that I have become accustom to from my 15" Q series!

The Q was presenting a 4ohm load on my amp so I by switching to dual 1ohm I hope to get close to 800W RMS from my amp. (the spec's show 2700Wrms into a 2ohm load but I am skeptical....)

I should clarify that I meant an additional 800W RMS, not total.

Edited May 24, 200916 yr by StickyFingaz

BTL seems like your best bet to me.

You need the BTL. It will handle the abuse you will most likely give the sub better.