BKOLFO4

Which face do you want the sub and port on???

I come up with the port as 16". . .not much difference. I would make the ports 17" long and use the Precision Sound Ports: http://www.partsexpress.com/pe/showdetl.cf...tnumber=268-352 With that much power, I would spec: Ohm: dual 1 P Chamfer: no Cooling: yes +$40 Flatwind: yes +$20 Daily or SPL: Daily Extreme Lead: no Universal: yes Brian

IA 40.1's are nice too. . .

The Fs of the 12" BTL is 40 Hz, the Q 28 Hz. But you actually made my point even stronger. . . There is a lot more to look at when selecting a sub than "Do I have the maximum amount of power this sub can handle, because if I don't, it is not worth buying." Brian

It is not just buying subs that you can push to the limit. . . BTL and BL's almost have to sound different just because of the way they are built. I wish I had a set of BL's just for comparison. According to the specs, the BTL is just shy of 3 dB louder with 1 watt input. . . It is about more than if you have enough power to "over power" your sub. The point I am making is that 1000+ watts will power pretty much any sub, and I personally have a pretty good feeling I would choose the BTL over the BL if I was not on a budget just for the way they perform.

If that is .35 DCR, you should be ok (more like .5 ohms impedance + rise). I am now running my 40.1's at .35 DCR with no problems, and as I understand it the 20.1 handles low ohm loads much better than the 40.1. Brian

Because we all know underpowering a sub will blow it. . . . j/k

If he has 20 ft^3, would you start that big for a single 18? I am just curious. . . .

I have run MT's and BTL's in the same enclosure. . . .The BTL's sound better and run way cooler playing music at high power for long periods of time (with the cooling option).

I have never built a 100% all out SPL only setup - Even when I wanted it to get loud, I still wanted to be able to play music. For my original dual 18" setup, I was space limited, so I went with the largest box I could and then tested port tuning frequencies from 30 to 63 Hz by pretty much cutting 1/2" at a time off of my port (yes the box got slightly larger each time.) Took readings - measured SPL, the actual impedance, true tuning frequency, and power output from the amplifier from 30 to 65 Hz for each port length. I then graphed all the data (tuning, box size, power, and output) and determined the length I wanted the port to be. My latest setup is just 12 ft^3 tuned to 35 Hz with 200 inches of port area. Wanted something that would get loud and do an awesome job of playing music. You can download something as simple as the spreadsheet on DIYSubwoofers.org and play around with frequency response of different boxes at different tuning frequencies. I use that spreadsheet a lot for designing boxes. . . Brian

With connections along the side is the "06" model, with connections on the end is the "07" model. Different designs. . .07 model is closer to the AX line. http://www.soundsolutionsaudio.com/forum/i...?showtopic=9312 Both are good amps.

I would. . .

That is not far off from where I am with my BTL's Is that NET volume after port and driver displacement? You could build a 2 piece box and connect them together after they are in the car. I have done that a couple of times. . . Brian

For a daily driver that you are going to compete with (looking for best SPL, but want to play music), I have found subs can work tuned up to 40-42 Hz, but definitely need the subsonic filter set correctly and you will find songs that are not as strong as they are with a box tuned to 35 Hz. If you are not going to compete with the system on a regular basis, I would not bother tuning above 35 Hz. For SPL only, there really is not a limit to the tuning. Music may sound terrible, but if the subsonic filter is set correctly, you will be ok.

(2) 12" Q's would be my vote, but that is enough power for a 15" BTL too. For the Q, you can get the BP option if you want, but not required with the power you are running. You would need dual 1 ohm coils. You wire the coils on each sub in series (making each sub 2 ohms), and then parallel the two subs making the final impedance 1 ohm. For the BTL, I would add cooling, 3rd magnet, HiXmCoil, Daily, and Universal. For a single sub, you would want a dual 2 ohm sub. Wire the coils in parallel for a 1 ohm load. Brian

I have run a pair of MT's on less than 1800 watts and they sounded great. I have run (4) BTL's on a single 40.1, sounded awesome. Nothing wrong with only running 1200-1400 watts to the BTL if you can afford the extra $$$ for the subs. Awesome sounding sub, and will get even louder when you decide it is time to buy more power Brian

If that is all you can get, use a 12" BL.

Use the box you have now to determine where your peak is in your car. You can change the port tuning and test (repeat over and over) and see what works out best. For SPL only, the box size and tuning work together to make the most SPL - the biggest box you can fit is not always the best solution. Testing, testing, and more testing. Brian

Mine are running at 0.5 ohm now. . .man they make a lot of power. . .

Hi!!! I am up in Denton, Tx. BTL - daily beater you want third slug, long coil, cooling, universal, and daily. Brian

4" x 21.5" is enough.

You should see the local shops when I tell them I run 4000 each to my subs. . .

you might can just replace the leads if the coil is ok. . .

If you are in North Texas, I can get you prices. . .

I remember that setup. . .