JIM1000

If installed just right, sure, I would guess low 140s tuned to 38-40 hz. Use a subsonic filter just high enough to not hurt your 40 hz output, like 35 hz.

So, can the (slightly better than) average guy do this? Will it leave my 18" assembly re-usable?

I need to downsize my 18 to a 15 or 12. I have 3-3.5 ft box max that I want to build. What is the process to obtain the kit, and how do it install it? Thanks Jim

How much to change a fully loaded BTL 18 to a 12 or 15? I need a much smaller box for my new truck.

It is a 06 Ford F150. Yeah I want to make sure it is tuned right so it does not unload. I had tried a Pion 3000 12" and a soundstream T2 12 in it, (2.5 ft@36hz) and this eats either of them, but I thought they should have been a lot louder too. Seems to be the truck. I have no doubt the woofer can do its part. Will be interesting with the 2200ish watts from the D3000. The 1200 does not like a 1 ohm load and shuts off when pushed. Did same with the SS 12. Will try and add pics tomorrow evening.

Here is a link to my box design. Have only ran a Lanzar 1200vibe on it so far as I am not convinced of tuning. Seems to get least cone motion at 33 hz when playing sine waves, so should be close. A bit inconclusive though. Actually the speaker is great, I am not impressed with the vehicle itself for bass. Does not sound as loud as my focus did with a lot less sub, but I know the focus probably loads bass a lot better. Box is 57w, 16.25 deep, and 20 high (6.5cf). The port is 14.75x7.5 and 28.75 long(area 110.6), firing up behind driver. The sub is facing forward on other side. This is supposed to be tuned to 35hz. link to box design I will be switching to my Lanzar D3000M when I upgrade wiring a bit, and confirm tuning. I did brace the box in the center with a full separator that I cut 4 square holes in leaving about 1.5" around box perimeter and 1.25" up and down if you can visualize what I mean. Does not seem to be a problem with box vibration, just vehicle vibration, will work on that some soon. Pics will be coming soon. Thanks for any ideas and especially if anyone finds a flaw in my box tuning.

Here is a box near what you asked for. Copy and paste the address, good luck. The program goofs up if port is too close to rear of box, you can change port size by changing woofer Xmax or tuning freq, or box size. http://www.subwoofertools.com/forum/ported...mp;Fs=&CE=0 link to box plan

IMO it is best if you can go down the middle in recommendations, 7-8 ft, 32 hz is plenty low, you dont want to tune so low the port is not helping your music, a 30 hz port does not help much at 45hz where most bass is, but you also dont want to tune to 45 and play something at 35. 10" of port is ok, 12-14 is better. 5 ft box will not play 30hz as loud with 18" sub as a 10 ft box, but will be louder at 50hz, when both boxes are tuned to 33hz. You can make a variable port if you want to experiment, just by changing port length or box or port volume. Good luck