Sub Box Design....Chpthril

[BCRider]

Using an online calculator I've come up with this. Was hoping I could get it proofed before moving ahead?

I'll have to make some legs for the box to raise it off the floor about an inch as the steering cable is going to have to pass underneath.

The other thing I wasn't sure of is the port itself and the best way to design it?

[chpthril]

it should be raised off the floor anyway, so thats ok that the cable runs under it.

Are you shooting for 40Hz?

With a round port, you are limited to using some sort of pre-made round piece, like PVC. You can go with those euro-ports, but you need to make sure its long enough and the box does not require it to make a turn. The other issue is that some of them have such a large flared nose piece that it often interferes with the woofer. A constructed square or rectangle port might be easiest. But it will require some recalculating is it consumes more internal space then a euro.

[BCRider]

Thanks Mike!

I was only shooting for 40hz based on the spec above. After that it's out of my knowledge base

Above does show the dimensions for the port if I was to make it more of a rectangular shape. In this case 1.7" x 7" x 10.9".....only because I was trying to make it slimmer than the ratio provided.

[chpthril]

1.75 x 7 gets you about the same port area, so the original port length would stay the same if you want to maintain the same tuning Hz, BUT, the .75" thickness of the port walls, reduces the net volume, which no effects the tuning Hz, forcing the length to change a little. It does not look like port length is constrained by the back wall though. I would net expect the length to change much due to the a slight change in net internal, in order to stay at 40Hz.

Was just curious if you spec'd it for 40Hz or ended up at 40hz

[BCRider]

I spec'd it at 40Hz

I'll have to figure out the volume of the port based on the material thickness then and see how it affects my other dimensions. Thx.

[Jetdriver]

I’m mounting a 12” under the helm in my 07 22VE. Ive yet to cut the hole to fit it in but the box is finished, tested, and pounds pretty good. You planning on a 10” or 12”?
I used a similar calculator online but made a rectangle box with a rectangular port. The website I used had a port calculator too. Made building it easy.
I got an RGB speaker ring off eBay for it and used rubber furniture feet to raise it off the bottom. If I build one again I’ll spend the extra money on good wood.

Here’s a couple pics of mine and the dimensions if it helps. I tuned mine at 34 hertz. Pardon my crude plans.

B3610EE9-1510-4EC3-8E8B-0907ABE9C701.jpg

FACAE1CD-3972-4FB2-9AB9-5B8C66D82734.jpg

34DEAE64-4BA0-4FFB-8A30-1B354322EDC0.jpg

11D8C9E1-3E65-4E81-92BB-4143F7C9F8DE.jpg

E1C56D87-CB27-46FD-AE68-2F92B9DEEFC2.jpg

[Surf406]

I did 2 xxx12 in my RZX2 and had to cut the helm out but it pounds 640F2842-9A25-452D-B1EB-B731A772A414.jpg

[BCRider]

Nice work!

I'm installing 12's. One is going under the dash and I do truthfully have a second one that I'm planning on installing in the port side locker. That will require an amp upgrade so it will wait a bit. I have the current 12 in the box it came in and it already sounds awesome. Let alone getting the single in to the right sized ported box and then adding a second.

[dukesofhazzard]

Gave up on the 10’s hey!!

[BCRider]

Dukes, Yep.lol. They definitely worked better than just a single but was wanting more. Some notes the two free airs could do really well and others there just wasn't much. I've always liked my bass and my friend/neighbor that has a ported 15" in his Malibu Response wasn't helping. He can make my whole house vibrate across the cul de sac.lol. That price was right at the time getting the second one of you and now they both have already moved on to a new home.



Mike, an update if you are still checking this. Hoping I now have all of this correct?

[chpthril]

I dont know anything about the woofer you are using, but i feel your port are is too small. I also think 40Hz is a little high maybe.

[KoolAid]

Is the software you guys are using take Thiele/Small parameters in account with your port frequency to come up with the enclosure size? Its been a long time since I have spoken this stuff and I need to work on designing an enclosure for the E30 sometime later this year.

[BCRider]

Mike, it's an Orion XTR Pro 122: