BKOLFO4

Run a 4" wide port on each side, or 8" in the middle. Run the port walls to 4" from the back and turn it and go another 1.5" parallel to the back wall. Brian

The 8" difference is correct. . . .The back panel butts to each side, the front panel butts up to the port, but overlaps the side for the .75" difference. Brian

I see people using that site all the time,. but I cannot ever come up with the same volume and tuning when I calculate it out by hand. If someone has tried, please show me the calculations. . .Look at the port length - it says it should be 32.5, but it is 29.5. Is 3" from the slot port effect? I thought it was 1/2 the width? How about the volume? I get a slightly higher net volume. Either way, the design looks good. . .you could go for a little less port area, get rid of the bend, and gain a little net volume if you wanted to. How much power you going to run? Brian

sounds like you are not planning on building a new box - just changing the port length. Don't forget, when you change the port length, this decreases the net volume of the box, which raises the tuning frequency. . . .depending on the design, many times I find when I make the port longer, all I have done is lowered my net volume and kept almost the same tuning frequency. Just make sure you calculate it out before you actually do it. you may have to actually build a new box instead of just making the port longer. . . Brian

Similar to the SS XXX 10000. I have seen posts on a couple of forums with people getting SLIGHT gains going from the SS10000 to the Opti6000. I owned the Opti4000D and loved it. Ran it on (4) AA Avalanche 15's in my suburban and on a (16) 10" setup for a couple of months. (2) batteries up front and a stock alt. Never had voltage problems. I debated for a long time between the Opti6000D and the IA 40.1s. I was able to pick up (4) 40.1's used for $3000, so I went that route. Brian

I do not have a PSP flare in front of me to measure, so I was just curious if all their flares worked out that way, or if that calculator was just an approximation. . . . Nice reading. . .I just designed a flare and am having it tooled for a 3.5" tube. Now I can calculate how long the port needs to be!!!! Brian

I have used the Lv calculator on the PSP website you reference above a couple of times, but it looks like all it does is add 1" to the standard calculated port length. . . .Does not matter what port size, box volume, # ports, etc. you use. Did I miss something?

Since most of the people following this build will never actually get to hear it, it is going to be a sad day when it is complete. . . .

I was told mine will have it. . . shipping tomorrow

When I get them (hopefully soon), I will run an IA 40.1 on each sub @ 1 ohm. Brian

I have heard the AX3200 can actually do around 4000 watts. If that is true, it might be ok if you are experienced and know what you are doing. . . .If not, I would guess that BTL may need a recone after a few weeks use with that kind of power. 4000 watts is a lot of power - don't care what kind of driver it is. If you have the $$$, run (2) 15's in the same box you were going to have for the single 18. Plenty of power for a pair of BTL's, and less stress for a daily setup.

I have less airspace and less port area for my (4) 15's. . .

Sounds like the perfect box for (4) 15's, not (4) 12's. . . .

aeros take less. . . Not sure on the 1/2, but less. I remember David at RE running (2) MT 15's with just (4) 4" aeros and doing 154's if Iremember correctly on the score. Inverting the subs. . .I am sure it is close enough, but the sub inside the box displaces more air than you gain when you invert them. Inside the box, the motor structure, basket, etc. take up airspace. You do not gain that with them inverted. All you gain is the 14" hole in the 1.5" thick wood and the volume inside the cone. Like I said, I am sure it is close enough, but it is not automatically the amount that would normally be displaced. Brian

Did you use 12.53 as the volume? You have to subtract the volume displaced by the ports, which is almost 1 ft^3. when you subtract that volume, the ports get longer, more volume is then displaced. . . Also, I don't think you gain as much inverting as you lose with them installed non-inverted. Quick calculation - volume inside the cone is 1/3 * area of the base * height. you also gave me a total height of 23" (12.5 + 10.5) above, which is 20.25" internal with a double top baffle. But it looks like you are on the right track and should be able to figure it out from here. . .just wanted to point out a couple of things you should double check. Messing up the port tuning on the high side can lead to over excursion and damaged drivers. . .

Aero ports will definitily work great, but (3) 6" ports is $$$ How far is it to the back wall using those dimensions, 3-3.5"???? You may want subs and drivers facing up. The dimensions you gave, with (3) 6" aeros, 15" long, subs inverted, top baffle 1.5" thick, would be around 11.25 ft^3 tuned to 33-35 Hz (not sure of the end correction factor with those 6" aero ports and I approximated the volume gained with the subs inverted). Should work out really nice. . . Brian

Yes. . ."3rd magnet: This simply adds more clearance in use for the HiXmCoil."

35 Hz is a low enough tuning on those drivers. . . For a port with that much area, I would assume you would do a big slot port. Do you have any overall dimensions for the box? I would be glad to help you with a box design. Brian

Thanks! Order placed

with a box that big, go with (2) 15's and something like a Lanzar opti6000D. . .

Hope those mirrors survive!!!!

BTL 12 should be around 57 pounds.

Can you make one of these threads that says "BTL" free cooling????

I wanted to, but it does not look like my suburban will be back together in time. . . .

What amp(s) are you using to get 3000 watts at 5 ohms? 122 volts is dangerous on the outputs Thanks! Brian