Two BTL 18's Enclosure Questions

[valin 0]

This is my first post on here, and need some advice from the BTL gurus

I just picked up two BTL 18's, dual 2's, fully loaded, and will be running them off of two modded Memphis Mojo MC-2000d amplifiers (1 on each driver at 1 ohm), approx. 3000 watts each. In my vehicle, which is a 2007 Toyota FJ Cruiser, I don't have a whole lot of useable space to work with and still maintain practicality, so the enclosure is going to be a bit tight for specs. I will run the subs inverted to try to save as much airspace as I can, but I only have a total of 11.2 cubes to work with, before port displacement. This is going to be a daily setup, and I am more than likely going to build it with a removeable ports so I can also tune it for SPL for comps. Subs will be facing up, inverted, and the port will be facing backwards with 3-3.5" to the tailgate of my SUV.

Can I get away with running these drivers with the airspace I have available? I know after port it will be 4-5 cubes. What do you recommend for port size and tuning? This is the first time I've run 18's, and Fi BTL's. Thanks in advance for the help guys.

[tejcurrent 13]

It's often better to leave room between the port and any obstructions, but if that's the design you've desided to go with, then roll with it.

It might not have the smoothest response, but it should be loud. I like mine in 5ft each, so as long as you try to stay close to that I'm sure you'll be ok.

32hz sounds great for daily imo, and the min. port area recommendation is 120sq for 10ft net, and 160 max. I think good bracing and a beefing up the baffle will do you good as well. Good luck- make sure to post pics!

[///M5 2,833]

If you don't have enough space for 18's perhaps picking up 15's would be a better idea.

[valin 0]

If you don't have enough space for 18's perhaps picking up 15's would be a better idea.

I've run 15's for years. I'm just sick of them and want to try something new. Besides, will I not benefit from having quite a bit more cone surface, even though I am a bit shy on airspace?

I know the 3"-3.5" to the rear door on my SUV isn't alot, but Meade seems to be pulling it off nicely. His tahoe only had about 3" to the gate.

[///M5 2,833]

If you don't have enough space for 18's perhaps picking up 15's would be a better idea.

will I not benefit from having quite a bit more cone surface, even though I am a bit shy on airspace?

It may be the opposite actually. Install is everything and you are forgetting that completely.

[valin 0]

I am certainly not forgetting that install has quite a bit to do with it. I am not sure how the BTL's react to smaller enclosures, so I asked the question.

I will be able to run 4.7 cubes per driver after displacement, while running more than sufficient power to the drivers, at 3000 watts per.

Fi recommends 5-8 cubes. Running the two 18's will give me 44% more cone surface area than running two 15's.

[JimJ 11]

If you want a peaky response...be prepared to get one

Then again, you're getting BTLs so a smooth response probably wasn't in the cards from the beginning...