BKOLFO4

Say what? Maybe you are talking about the gaskets being messed up where the screw heads went through?? those are #12 steel screws and they are all the way to the basket. I actually hit the drill a little hard and popped the head off one. . .That is why the lower right sub is now twisted clockwise The head is just larger than the hole in the gaskets, and it messes them up as they run through, but believe me, they are all the way through. I would have liked to have moved the gasket out of the way and shot the screw in, but it is too hard when installing these subs alone. I learned my lesson about drywall screws and high powered subs. . . .Popped all the heads off of a blueprint 1803 and it fell out funny, first time I emailed Scott, he said he remembered me from way back when I had the 1803's. . . . brian

Post #17 in this thread.

If you want to cut the car - 2 BL 15's If not, one 15" BTL. I run my BTL's in 3.15 ft^3 each. You could get away with less airspace for the pair of BL's if would keep from having to cut the car up. . . Brian

I thought space was a problem??? (2) BL 15's require double the box size of the single BTL 15. . . . Brian

What is funny to me, as pointed out in that article and I have pointed out many times to my friend who spends big $$$ on just the 2 ft of wire inside the speaker, people claim to "hear" a difference with a short distance wire change. What about the 100+ ft of wire in the voice coil or crossiver inductors??? That current is traveling a LONG path for 2 ft of wire to make a big difference. Power cables is another one. Same guy I know has power cables for is tube amps that he paid $300 each for. I give him a hard time, because they are plugged into $10 surge protectors!!!! How about the wiring in house? I would have spent the money on a good line conditioner, although it seems to me if the amp has a good power supply, it really should not make much difference. . . .

I found in my suburban (before the wall) that subs back, port back was best for music and on the meter. It is also nice when I needed to haul something long that had to be laying over the top of the box

Use your amp and buy dual two ohm subs like you mentioned above. . . .less stress on the amp and plenty of power for a pair of BL's. EDITt - you might also want to post the question on a couple of forms if that amp actually makes that much power. I have not seen many $350 amps that actually make 3200 watts RMS. I would be more concerned about the box size for 2 18's than the amp. I ran an avalache 18 in 4.55 ft^3 (before displacement), and it was ok. Before I cut the baffle for the 18, I was running an avalanche 15 in the same box and it sounded MUCH better. I rebuilt the box for the 18 at 6.5 ft^3 and it was a big improvement. . . Brian

After displacements you will be running each sub in 4 ft. How hard would it be to rebuild that baffle?? I think you will be happier with 15's. As far as "underpowering" a BTL, 1600 watts RMS is plenty of power for a BTL. I love to over power subs, but 90% of the time I bet my subs see less than 500 watts each and they sound awesome. (I know many people will disagree with me). Not sure what to tell you on the power rating. . . Are you the type that drives around at full volume all the time playing every song you can find with the deepest bass? If you know what you are doing, you will be fine, if not, you will be posting "I need a recone for a BL 18" in a couple of weeks. . . As scott has said over and over, if you run that much power, make sure your subsonic filter is set correctly!!! Brian

Sounds like you already bought drivers, but if you have not and that is 8.5 ft^3 total, I would suggest you go with 15's, not 18's. You could do a pair of BTL 15's with the cooling option for $100 more than the BL 18's with cooling option and flatwind coil. It has been said over and over - The drivers are rated for what Fi feels is safe. Some people actually manage to mechanically kill drivers with less power, while others have no problem with a lot more. . .

They are 1/4" x 1 1/2" square edge copper. $32 each at: http://www.mcmurraymetals.com/ He is in Dallas and will ship. . . Brian

Been a few days, but here is what I think: The BTL's sound pretty much the same as the MT's, but the BTL's are a little stronger down low. I like the fact that they still kick up in the higher bass frequencies like the MT's do. Now I know there will be haters on this (I had countless PM's stating I was making a mistake going from MT's to BTL's), but on the meter, the MT's were louder (by 1 dB on a burp, and 0.7 dB playing music), but I was running each MT on a strapped pair of MD3D's at 1 ohm (before impedance rise), so they should have been doing around 4000 watts even after impedance rise. I am running each BTL on a IA 40.1 at 1 ohm (before impedance rise), so with rise, I doubt I am getting 4000 watts to each BTL. In the next couple of weeks I will rewire the 40.1's so they are strapped at 0.5 to see what kind of numbers I get. I will post results when I get around to trying it. The way my amps are mounted, changing speaker wires around is a pain. I think I am going to build a speaker wire connection plate to make it easy to change tham when I want to burp. For music (to the ear), the BTLs sound louder due to the increased lower frequency output. The three people who ride the most in my vehicle all commented that the low frequency was noticably louder without me saying anything to them about the meter results. And the best part (the main reason I made the switch), amps and subs will pound out music for long periods of time without straining anything. . . .MT's after 30 seconds were hot and had the funny smell to them. The BTLs play at 154-155 dB for long periods of time without any problem. I ran them hard on and off all day Saturday at a show in Frisco (85 degrees outside), and the dustcaps felt warm every now and then, but never really hot like the MT's would get. Of course I have already stated I am running less power to the BTL's, so that is part of it, but to lose less than 1 dB playing music and be able to do it all day long instead of for 30 seconds is worth it to me. I will also note on the loudness - Scott told me straight up that the BTL's would not meter as loud built with the full cooling and daily options due to the increased air gap and metal machined out of the pole for the cooling channels. . . If you have ever sat in a car playing music with bass centered from 36 to 40 Hz at 155 dB, you know I still have more than enough output for a daily driver. . . Brian

If it is a slot port (shares a wall with the side of the box), it can be shorter. Use this: http://www.carstereo.com/help2/Articles.cfm?id=31 That is not much port area for a BTL 18. You would be better off with 7 ft^3 and more port area. At least 80 in^2, and 100 in^2 would be better.

Yes. . .I live in Denton. Brian

Can I ask how? All 12 one ohm coils in parallel = 0.08 ohms each driver's coils in series, then all in parallel = 0.33 ohms three 1 ohm coils in series, then those four sets in parallel = 0.75 ohms four 1 ohm coils in series, then those 3 sets in parallel = 1.33 ohms six 1 ohm coils in series, then those 2 sets in parallel = 3 ohms all 12 coils in series = 12 ohms I think you mean go with Dual 2's, wire each driver's coils in series, and then parallel all 6 drivers to get 0.6667 ohms. . . Brian

I just bought 15" BTLs. . . Already have at least 10 hours of beating on them. I have yet to hear any lead slap. Matter of fact, all I can hear now is something ringing in the distance. . . Brian

That driver will work in a wide range of enclosures. Anywhere from 8-10 ft tuned to 20 Hz will work nice if space is an issue. If it was me, and space was not an issue, I would build a 30" cube with 1.5" thick walls (around 12.5-13 ft net), and tune it to 18 Hz. I have run one in 4.3 ft^3 tuned to 30 Hz in a car and it was awesome. . . Brian

Maybe I will crash into that UPS truck and then sell mine in the classifieds for $100 each, since I am not using them.

Just to give you an idea, I ordered my (4) on 10/24 and they were sitting at my door when I got home from work on 11/7. 2 weeks. Worth every minute of the wait. . .

$%^ %^$&$# $#%^&*!!!!!!

Won the competition at car toys this weekend. 7 ft tall trophy!!! (sorry Lord Baccus) It did a 155.8 @ 38 Hz. Little low, but amps are really not wired to burp right now - I really setup this system to play music at extreme levels without worrying about anything blowing up, and it does an awesome job of it. I played music multiple times for extended lengths of time in the 154+ range. . . amps were not even getting warm, and the sub dustcaps were barely warm a couple of times. I am going to measure the actual impedance rise, and see what kind of power I am actually getting out of the 40.1's. Then sometime when I am bored, I will strap the amps on each pair of subs and burp it to see what this setup can do. Brian

Subs are starting to break in a little after the ride to work and the round trip to lunch. They guy that goes to lunch with me everyday said, "man, there is something different about those subs. They just like pound on you deeper and harder than the other ones you had, and they don't even seem to break a sweat - look at them, they are barely moving.". . . . I will say right now (and I don't know what they do on the meter yet), the BTL's sound way better playing music than the MT's did. And maybe it is the combination of the subs and the better amps, but the system as a whole sounds much better playing music. . . Brian

Man I forgot to say - I love the BTL's. :D

I will be in and out. You still have my cell number (I will PM it to you)?? I am going to be in Frisco on Saturday - maybe we could meet up there.

1:20 am and it is ready to go. . . .

That is a "music" install. Amps are not connected yet. Need to add the fuse holders in line on the power wires and connect the power/ground to the batteries.