bkolfo4

I almost hate to say it. . . I just draw them in MS paint. I have a few templates drawn and use those.

Does this help??

Yes. Depending on how much bracing and how much you round the port edges, you will be between 33-34 Hz tuning. Brian

Just ran in here and checked the dimensions. If you build the port as my picture shows above and use the overall dimensions of 13W x 16H x 25D, assuming .21 driver displacement and a double baffle, you end up with 4.5 cuft net volume tuned to 32.5 Hz. If you want it tuned a little higher, knock 1" off that port wall length. I woudl also roundover the edges on the inside end of the port wall before you install it, and then roundover the port opening on the outside of the box.

I do not want to offend anyone, but I have corrected a lot of boxes that this program has calculated. I have yet to see a perfect program for L-shaped ports. I can check on the latest dimensions it gave for your box tomorrow. Brian

I think I have already said several times that using the 19.5" piece results in a 25" port. . . Does this help you see it?

You have to add the length through the center of the 90 degree bend too. You have a 32.75" port there. If you just put the 19.5" piece in there, and then add the length through the 90 degree bend, you have 25". Any time you stop the port wall so the opening between the port wall and the back of the box is the same dimension as the port width, you add the length through the center of the bend.

If you can go 30" deep it could work. Not the best case, but would work. Something like 7 cuft tuned to 34 Hz with a 15.5" x 6" port. If that sounds good, PM me an email address and I will send a quick drawing. Brian

What you have drawn there looks way off. . . 1. a 3.5" opening inside the box is not correct if the outside opening is 4". 2. the program says you need a 22" port, you have drawn a 40+ in port. 3. from your commenst, you are mixing up port length and port area. . . For the 31 x 25 x 16 dimensions you posted, you need to just get rid of the back port wall and make a port from the single 20.25" dimension (into the box so it is 4" from the back wall). I would also double the baffle making it 1.5" thick. The result is 4.5 cuft tuned to 32 Hz. Brian

Fi BTL or AA Mayhem. If you have the extra $$$. 2 15's in the same airspace as 1 18 will be louder. I have run BTL 15's in less than 3 cuft tuned to 34 Hz and they still sound awesome.

I do it all the time on Sonotube builds and have never had a problem. . .Not sure how much difference it makes. Thanks for the comments guys. Fired it up last night. Very clean sounding low bass. I like it. . . Brian

Used a modified 15" Q that Scott built up for me (I think he reduced the power handling, since I am only using a 500 watt plate amp, I did not want to blow the sub by under powering it. . .haha). 500 watt PE Dayton plate amp. 8 cuft net with (2) 4" Aero ports tuned to 21-22 Hz. Just shot texture on it - he is going to paint it to match the room and it goes in the corner. This is part of a HT job for this customer - Really nice setup. Epson 8500UB projector with 120" screen (awesome projector). 7.1 with nice in-walls and this sub. Denon AVR 4310CI receiver and Sony BDP-S470 Blu-Ray player. Big room - 22' deep x 27' wide. Brian

It is the minimum distance, not max. More is better. . . If I was using a 6" aero, I would stay 5-6" from the back wall.

Why does "fresh paint" mean no clear coat??????

I used the AC Matrix in my van since I had 6 subwoofer amps. Not using it in my new setup. If you decide you want one, I will sell mine for $100 shipped. Great line driver.

T-Mobile? Sucks it will only run on Edge network on T-Mobile.

I know about motor break in. You missed the point of my post, or you just wanted to be an a$$. The point of this post was not to get into motor break in. The point was taking it easy on the sub does nothing for breaking it in. . .nothing more.

Gotta play it hard to break it in. Not like an engine. Engine still turns full stroke at low RPM. If the sub is not moving, the suspension is not stretching out and breaking in. When you know everything is hooked up correctly, let it rip!

Sub decision is a toss up. Either one has potential. Ported is the main area you need to stick with!!!!! Don't even think sealed

Last couple of questions, and then I can put together a box design: Are you wanting the front to be 85cm to make it like a wall? You actually have more than enough room there, so I can take some off the width, the depth, or not make the front as tall if you are not trying to make it into a wall. Is this to compete, play music, or both (do you know what you want it tuned to?)? How much power are you going to run on this sub? PM me and email address as it is easier for me to send the design that way. Brian

I forget, but I think shorting the second coil keeps the t/s parameters close to the original values. Don't quote me on that, I'll claim I did not say it if it is wrong.

Sorry, but this reply is wrong. You can connect just one. Power handling is cut down, and the t/s parameters can be varied by leaving the second coil open vs. shorting it. It is not going to hurt the sub.

Tang band 8" on sale at PE for $50 each are nice: http://www.parts-express.com/pe/showdetl.c...tnumber=264-854 edit - sorry, they are single 4 ohm.

You have a lot of space there. . . Since the box drops back at such a slant, you may be better off running a port across the top or bottom. Are you going to compete with this setup, or just building a loud music system?

I wanted to say something, but the way this thread is going, I bit my tongue.