Featured About IB Enclosures

[Blackout67]

Yeah, really I think any of the modern super huge xmax subs might work well for sort of IB in a trunk. Like you do 2 high xmax sundown 15's, there's so much air movement there you might actually be able to make pressure in the trunk to support the cone and add more power. Idk woofer maybe like the nightshades, I'm not up to date but they used to have 54mm of one way xmax. I've seen sundowns used in full horn walls at high power at like 155-160db in the 20 hz range, where the horn loads more like ported because there's so much sub in a tiny space, the air in the entire vehicle reaches such a high pressure, it allows mechanical loading in the horn line regardless, cone control more like ported vs free air. I'm just saying if you do IB in a trunk and get enough xmax back there you might actually be able to dump some power into it, but you know this is all talk.

I have a busted Skar ZVX my friend say I can have for free. Just needs reconed but ive ever done a recone before lol

 

[Buck 5,000+ posts]

I have a busted Skar ZVX my friend say I can have for free. Just needs reconed but ive ever done a recone before lol

Just from what I'm picking up, it sounds like you just need to decide on something and run with it. Nothing will ever be perfect, and you'll just have to learn along the way, but that's what sound is about, to me at least. Idk if anyone here can show you how to do this to absolutely guarantee results, you're just going to have to pick the best for your budget and space and all. I know back in the day I did like a 135 db with a single DD 3510 tuned to like 28 hz in a friends Camaro. But like with IB, the nature of it, that work is up to you. Just gotta get the best woofers you can if that's the route you take.

 

[Blackout67]

Just from what I'm picking up, it sounds like you just need to decide on something and run with it. Nothing will ever be perfect, and you'll just have to learn along the way, but that's what sound is about, to me at least. Idk if anyone here can show you how to do this to absolutely guarantee results, you're just going to have to pick the best for your budget and space and all. I know back in the day I did like a 135 db with a single DD 3510 tuned to like 28 hz in a friends Camaro. But like with IB, the nature of it, that work is up to you. Just gotta get the best woofers you can if that's the route you take.

Yea im not really set on anything in particular really. Just wanted to see what other pipe experience with IB is like and if itd be worth it.

Im not opposed to going port, sealed, IB or whatever I just want it to sound good and be efficient and cost effective. A sheet of MDf is the same price no matter what box im gonna be building. So really the defining things would be woofer price, which what im seeing here is that IB drivers are going to be pricey and if im doing a build im going to do a build I want it to be the best driver I cam get for that application within my budget and IB subwoofers dont align with that.

Here's another question: I was designing a ported box with aeroports and I was looking at a single larger port vs 2 smaller port for a 12 inch enclosure. I was gonna use either a single 4 inch aero or 2 3 inch aero.

Now the main advantage ive seen bigger ports is reducing port noise. So the way i see it, two 3 inch ports has more area than a single 4 inch port. But from what ive read on forums, the port noise would be too high because the ID is 3 inches. But there's 2 of them so surely it would equate to lower port velocity right? Could someone explain that to me

 

[Buck 5,000+ posts]

In general all you do is the raw math. You do pi x r^2 to find the surface area of the ports then multiply by number of ports. The bigger overall surface area is usually better, lower port noise. But there's ways to calculate that too, actual port velocities.

 

[Jimi77 Premium Member]

This was one of tbe first ones that popped up when I searched IB woofers. The price point kinda scared me away cause I was looking at getting at least two of them snd thats would be over $500 after taxes with two.

You think one 15 would be good if itd fit?

Looks like it's out of stock. The Dayton UM has very similar specs except you'll probably need 500wrms for an IB. It also has double spiders and and a rubber surround. 130db from a single 15 in an IB - probably not. Probably not with 2x 15s. For 130db, you'll need to consider ported or bandpass designs. Also if you're trying to hit 130db, you probably want an enclosure to control the cone.

 

[Blackout67]

Looks like it's out of stock. The Dayton UM has very similar specs except you'll probably need 500wrms for an IB. It also has double spiders and and a rubber surround. 130db from a single 15 in an IB - probably not. Probably not with 2x 15s. For 130db, you'll need to consider ported or bandpass designs. Also if you're trying to hit 130db, you probably want an enclosure to control the cone.

Yea thats what is sounding. Prolly gonna go ported with wither a couple 10s or a single 12

 

[Blackout67]

In general all you do is the raw math. You do pi x r^2 to find the surface area of the ports then multiply by number of ports. The bigger overall surface area is usually better, lower port noise. But there's ways to calculate that too, actual port velocities.

Yea I know you can put in WinISD to figure all that out, I just wanted to see why that is the case.

You are are saying the actual inner diameter of each port on its own is irrelevant and you need the combined port area from the two of them? Thats what makes sense to me, im confused why the port velocities would be calculated with the single 3 inch one vs the combined area of the two

 

[Jimi77 Premium Member]

Yea thats what is sounding. Prolly gonna go ported with wither a couple 10s or a single 12

There will be more selection for those type of subs too.

 

[Buck 5,000+ posts]

Yea I know you can put in WinISD to figure all that out, I just wanted to see why that is the case.

You are are saying the actual inner diameter of each port on its own is irrelevant and you need the combined port area from the two of them? Thats what makes sense to me, im confused why the port velocities would be calculated with the single 3 inch one vs the combined area of the two

Don't overthink it, it's just total port area for the chamber. So you have to add all your port areas together if you have multiple ports. Total port area is what matters.

The simpler version of winisd used to not calculate multiple aeroports right, it would be much lower velocity than it should be, idk if that's still the case, the "pro" version is correct or at least correct enough, usually. Haha

I do tend to prefer slot ports though, Aeros can be difficult sometimes. But whatever works.

 

[shredder1 10+ year member]

So the way i see it, two 3 inch ports has more area than a single 4 inch port. But from what ive read on forums, the port noise would be too high because the ID is 3 inches. But there's 2 of them so surely it would equate to lower port velocity right? Could someone explain that to me

7in2 x 2 is greater than 12.5in2 so yes... a single 4" has less area but more wall... lol. Plus length can become prohibitive with a larger port area especially with Aeros. I always shoot for a single vent keeping velocities under 150ft/sec if using an actual Aero. Remember an actual Aero has a legit flare which reduces boundary turbulence and effectively increases laminar airflow along the wall surface.

 

[Blackout67]

Don't overthink it, it's just total port area for the chamber. So you have to add all your port areas together if you have multiple ports. Total port area is what matters.

The simpler version of winisd used to not calculate multiple aeroports right, it would be much lower velocity than it should be, idk if that's still the case, the "pro" version is correct or at least correct enough, usually. Haha

I do tend to prefer slot ports though, Aeros can be difficult sometimes. But whatever works.

I use a cheap program to make simple box designs. With Aeroes it makes the cusheet more reliable have even cuts vs when I mock up a slot ported one, the cuts are super uneven with lots of decimal ports. With slot ports you have to do extremely small adjustments to port area, box volume, and tuning frequency to get exact cuts which can take so long. Thats why I was wanting to go with aero port. Also because ive never done an aero port build and I think they are much cleaner and better looking

 

[Blackout67]

7in2 x 2 is greater than 12.5in2 so yes... a single 4" has less area but more wall... lol. Plus length can become prohibitive with a larger port area especially with Aeros. I always shoot for a single vent keeping velocities under 150ft/sec if using an actual Aero. Remember an actual Aero has a legit flare which reduces boundary turbulence and effectively increases laminar airflow along the wall surface.

Yea thats what I was looking at. I saw a technique with steel dog feeder bowls where you heat it up and press a PVC pipe into it to create the flare. PVC is pretty cheap

 

[shredder1 10+ year member]

Yea thats what is sounding. Prolly gonna go ported with wither a couple 10s or a single 12

I'd definitely go with a pair of decent 10's ported myself. Every Mustang I've heard turns heads with "only" a pair of 10's... haha.
If it'll fit thru that notoriously small trunk opening I'd say go bigger but a pair of 10's ported usually fit.

 

[shredder1 10+ year member]

Yea thats what I was looking at. I saw a technique with steel dog feeder bowls where you heat it up and press a PVC pipe into it to create the flare. PVC is pretty cheap

Making Aeroport flares may be a little tricky to do it right. That looks about right may not actually be accurate when you discuss all the factors involved.

My BAP 10" added a bunch and the outer flare was like 15.75". The inner flare was 12 and change.

 

[Buck 5,000+ posts]

I use a cheap program to make simple box designs. With Aeroes it makes the cusheet more reliable have even cuts vs when I mock up a slot ported one, the cuts are super uneven with lots of decimal ports. With slot ports you have to do extremely small adjustments to port area, box volume, and tuning frequency to get exact cuts which can take so long. Thats why I was wanting to go with aero port. Also because ive never done an aero port build and I think they are much cleaner and better looking

That's exactly why I like slots is I can sort of perfect them, aeros you're just kind of stuck with whatever you have size wise. Anyways, just whatever works really. As long as it's proper.