valin

sweeet. thamks man Flakko, your avatar kinda looks like Michael Jackson with a dirty mustache!

I see that the cutout for an 18" BTL is 16.75" when mounted normally. Is the cutout the same size when the driver is inverted, or does it have to be a bit bigger?

Thanks alot guys, I really do appreciate the help in this.

Where can I purchase the Aero ports?

Using a double baffle on top would give me a total of 20.75" in height. The 18" subs displace 0.26 cubic feet per driver, right off of the Fi site, so by inverting them I would be saving 0.52 cubes. The calculation program takes the volume consumed by the ports into account, as well as volume taken up by drivers (although it uses 0.33 cubes per driver). It's kinda nice actually. To achieve my acutal volume of my enclosure, which 12.01 cubes before displacement, I have to use 48 wide, 22.25 tall (to make up for the extra top baffle), and 23 wide. The program then wants to take up 0.66 cubes for the sub volume, so I have to add that back in. So, i ended up using 48 wide, 23.4 high, and 23 wide, just for the program to give me total volume in the enclouse after driver displacement at 12.01. Then, using three 6" aeroports at 11" long give me 84.82 sq. inches of port area, and a tuning freq. of 33Hz, and consuming 0.63 cubes of space, leaving me with a total of 11.38 cubes after all displacement. If I ran two 8" ports, they would be 14" long for 33Hz tuning, giving me 100.53 sq. inches of port area. The 8's would consume 0.92 cubes, leaving me with a total net of 11.09 cubes. Some people are saying that with using aeroports, you still need the same port area as using slot ports.....not half like what George mentioned. I have been trying to find this elsewhere to verify, and I am having trouble understanding why this would be. If that was the case, Where is a good place to purcahse the aero's?

Ok. I've been looking into the 6" Aeroports, and found some calculators. http://www.audiogearreviews.com/tech/tools...r-rectangle.asp Using this calculator, and a box width of 48" as an average, 22.25" tall for the double baffle, width of 23", leaving me at 12.01 cubic feet total before displacement. Each driver takes up .26 cubic feet, so I adjusted the box dimensions to accomodate for another .52 cubes, for a total of 12.53 before displacement. With three 6" Aeroports, it is giving me a length of 11" for a tuning frequency of 33hz.

Yes, I have 3-3.5" to the rear hatch. I don't see there being a problem with that. Steve Meade only had about 3" to the rear hatch in his Tahoe, with twice the drivers, and 16000 watts of power. I'm going to check in to Aeroports right now. Thanks guys.

Thanks alot. I really appreciate the help. My old system consisted of two 15" Memphis M3's in a 7 cubic foot enclosure, tuned to 44hz. They were powered by one Memphis MC-2000d Mojo amp. It wasn't nearly deep enough, but it hit fairly hard. I was pushing a best of 149.7 db, on an older mic (i'm not sure which one). It really fell off hard on the lows. I've been watching some vids of people doing the infamous "hair trick", and would love to be able to do that. Time will tell i suppose.

The box is a "T" shaped enclosure to go around the wheel wells. The bottom is 42" wide, 23" deep, and 10.5" tall. The top of the box is 53" wide, 23" deep, and 12.5" tall. Subs up, inverted so they don't take up internal volume, port back. Hopefully this link for the image works. Clicky for the box

What would I need to run for Aeroports to maximize output, and tune down to 32 or 35 hz?

Ok, I can probably get it up to 13.81 cubes, before port displacement. It won't look as good in the vehicle, but it'll have to do. What should I tune the box to for daily? I was thinking 32 hz. So, if I go with 165 sq. inches of port (the minimum 12 sq. inches per cube), how long would the port have to be for 32 hz? Is this enough port size? What are your box recommendations? I really appreciate the help guys.

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. 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........so am I wrong to think that it would be more beneficial to use 44% more cone surface area and cut back slightly on space than to drop down to 15's? This is going to be a daily setup, and I am more than likely going to build it with a removeable port 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? This is the first time I've run 18's, and Fi BTL's. Thanks in advance for the help guys. I have asked this question in other locations.....i'm just looking for more opinions. Thanks in advance guys!

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.

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.

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.