New to IB

**ivseenbetter** · **11-02-09, 11:05 AM**

I’m really like the “idea” of an infinite baffle setup. It looks impressive when I see all the photos of everyone’s setup. It also tickles the DIY bug a little too which increases interest in this kind of project. Right now I have two MFW-15 subs in a room that is roughly 5500 cubic feet. They do a good job in this room. However, I want to clear up the floor area so that my kids can play in the room and I don’t have to worry about them playing with the speakers or the associated wires. So I am thinking a IB system in the attic will be a good replacement for what I have.

I’m beginning the “study” phase where I look into what it actual takes to build one of these systems. So far it seems like there really isn’t an exact science for building an IB as there are a ton of factors that need to be considered based on what I have read. So, I have a couple of basic questions to start out with:

1. Is there a good parts list that somebody has already built? I’m not looking for specific brands necessarily, but just a list of things I need to shop around for…obviously I need subs but I am sure there are is probably a lot of minor things like speaker wire, MDF, and other pieces that I need to start looking for.
2. I live in a Cape Cod style home which means I have deep slanting roof. I have a very long attic so there is plenty of room up there, but at the same time, I believe placement will end up having the manifold within a few inches of the roof. With one of the woofers pointed in that direction is there any concerns/issues that having this roof so close to one of the woofers cause?
3. Can a good IB system be built that will fill my room for around 1K?

These are probably dumb questions, but like I said, I am just starting out so I really just needed to start gathering basic info and see if any harder questions come up once I get these basic concepts off my mind.

Thanks,

Chris

**Bob_99** · **11-02-09, 11:28 AM**

As others on site would tell you, there are no dumb questions.
And while I'm by no means an expert on IBs, I looked long and hard at building one and after a lot of reading I still could not convinced myself that the temperature variations the speakers would be exposed to would not make a significant difference to the performance. I live in New England so winter would be near freezing and summers would be over 100 in the attic.

Bob

**ivseenbetter** · **11-02-09, 11:32 AM**

I hadn't even thought about temperature variations! Good point. I live in Virginia...and while the winter isn't really "freezing" it does get cold, and summer is very hot. What kind of impact will this have on an IB?

**evilskillit** · **11-02-09, 12:00 PM**

Several companies make IB specific drivers like Dayton Audio, Fi Car Audio, Exodus Audio and Acoustic Elegance just off the top of my head. If you are going to get new drivers get some of these IB specific units. You can get 4" IB drivers from Exodus Audio for like $540 and an amp for under $500 so that would be a very nice set up for under $1000. Or if you were planning on spending close to $1000 you can always get more drivers.

The Manifold is pretty easy to build, its just a plywood box with holes in it. Mounting it into the ceiling is a bit of work but thats on you to figure out. Then just wire it up and go. Collo's Diy subwoofers has some good info on his IB sub build, and there is a forum dedicated specifically to infinite baffle called The Cult of the Infinitely Baffeled. Check them out.

As for temperature it will affect the drivers. Hotter makes the suspension more compliant and the surround softer. Colder has the opposite effect. However I'm guessing with a lot of really big woofers and a lot of power you'll never notice the difference.

**Mike P.** · **11-02-09, 12:14 PM**

The biggest issue is finding the best location for the IB.

**Bob_99** · **11-02-09, 12:22 PM**

As I mentioned previously, I'm no expert but if you go to

http://www.mp3car.com/vbulletin/car-...rformance.html

and read post #7, then you'll get an idea of my concern. This is for a car which will warm up whereas most attics do not. Also, some speaker manufacturers give temperature operating ranges but many don't. Also understand that I'm not trying to dispel the notion of an IB but just expressing something that's not been clearly proven when building an IB. People who can put the speakers in an environmentally control room are very fortunate.

Thanks.

Bob

**evilskillit** · **11-02-09, 01:58 PM**

Yeah. Ive read about how temperature affects the parameters of speaker drivers. I don't think attics get all that insanely hot or cold and most of the subs that we use for DIY HT are also suitable for cars, which I believe can get hotter and colder than attics on average.

I did see one crazy guy who built an IB in his living room and put the subs literally outside of his house and then just covered them with some louvered wood doors. The things would have been exposed to heat, cold and extreme moisture. He said they had been that way for a few years and still worked just fine. Now I would never do THAT to nice subs. I'm sure it signifigantly shortens the life span but I think attic mounting is probably fine, so many people do it. If it does slightly lessen the life span of the drivers chances are in 5-10 years you'll either have moved or be interested in an upgrade anyways.

**cdy2179** · **11-02-09, 01:59 PM**

Quote:

ivseenbetter wrote:

I hadn't even thought about temperature variations! Good point. I live in Virginia...and while the winter isn't really "freezing" it does get cold, and summer is very hot. What kind of impact will this have on an IB?

Don't forget in the winter the heat from your house will rise to the ceiling and into your IB enclosure. Your IB will be stay much warmer than you think.. not toasty..but a lot warmer than your attic temp.

Your summers aren't as hot as the south and mid-west and IBs haven't been affected by heat in these places.

I wouldn't worry about it.

**ivseenbetter** · **11-02-09, 02:01 PM**

Quote:

evilskillit wrote:

Several companies make IB specific drivers like Dayton Audio, Fi Car Audio, Exodus Audio and Acoustic Elegance just off the top of my head. If you are going to get new drivers get some of these IB specific units. You can get 4" IB drivers from Exodus Audio for like $540 and an amp for under $500 so that would be a very nice set up for under $1000. Or if you were planning on spending close to $1000 you can always get more drivers.

The Manifold is pretty easy to build, its just a plywood box with holes in it. Mounting it into the ceiling is a bit of work but thats on you to figure out. Then just wire it up and go. Collo's Diy subwoofers has some good info on his IB sub build, and there is a forum dedicated specifically to infinite baffle called The Cult of the Infinitely Baffeled. Check them out.

As for temperature it will affect the drivers. Hotter makes the suspension more compliant and the surround softer. Colder has the opposite effect. However I'm guessing with a lot of really big woofers and a lot of power you'll never notice the difference.

I'll definitely take a look at these. Seem to be priced about right in my book. Thanks for the lead!

Quote:

Mike P. wrote:

The biggest issue is finding the best location for the IB.

Would finding the best location work by running a sub in the listening position and then putting a mic up against the ceiling in the locations I am considering and then looking for the best response? If so, then it should be similar to placing a typical in room sub.

**Mike P.** · **11-02-09, 02:06 PM**

Quote:

Would finding the best location work by running a sub in the listening position and then putting a mic up against the ceiling in the locations I am considering and then looking for the best response? If so, then it should be similar to placing a typical in room sub.

That should do it.

**ivseenbetter** · **11-02-09, 02:47 PM**

How difficult is it to attach the manifold to the ceiling joists (I believe I have 16" spacing)?

**Bob_99** · **11-02-09, 03:21 PM**

Depending on how much space you have above your position, it's not hard at all. Have you checked out some of the projects over at the cult?

http://ibsubwoofers.proboards.com/index.cgi

Bob

**FlashJim** · **11-02-09, 03:33 PM**

If I remember correctly, my volume was about 4800 cf. My original sub was a sealed 15" and it filled the room nicely. I went with 4 18's for my IB. My pics are on here somewhere.

It's a very fun build. I wouldn't hesitate to do it again.

**ivseenbetter** · **11-02-09, 03:43 PM**

Quote:

FlashJim wrote:

If I remember correctly, my volume was about 4800 cf. My original sub was a sealed 15" and it filled the room nicely. I went with 4 18's for my IB. My pics are on here somewhere.

It's a very fun build. I wouldn't hesitate to do it again.

How loud is it outside of the house. I have neighbors.

**Mike P.** · **11-02-09, 04:11 PM**

There are IB builds in the Database to see the manifolds. Just click on the link in my signature.

**FlashJim** · **11-02-09, 04:41 PM**

Quote:

ivseenbetter wrote:

How loud is it outside of the house. I have neighbors.

It's not. I had the same concern.

Be sure to secure everthing on the wall. I've broken MANY things over the last year or two. The ceiling fan globe fell, pictures fall off the wall, etc.

**evilskillit** · **11-02-09, 06:35 PM**

Btw, I read a bit about box construction material over the last few days. I'm not sure how you're getting this box into your attic but you might consider plywood. Depending on who you ask its just as good as MDF and if you have to carry it up a ladder and or into a crawl space you'll be glad you went with the lighter material.

**ivseenbetter** · **11-02-09, 06:59 PM**

Quote:

FlashJim wrote:

It's not. I had the same concern.

Be sure to secure everthing on the wall. I've broken MANY things over the last year or two. The ceiling fan globe fell, pictures fall off the wall, etc.

Really? Then will it affect the projector that is mounted to the ceiling in the same room this will be installed in?

**ivseenbetter** · **11-02-09, 07:00 PM**

Quote:

evilskillit wrote:

Btw, I read a bit about box construction material over the last few days. I'm not sure how you're getting this box into your attic but you might consider plywood. Depending on who you ask its just as good as MDF and if you have to carry it up a ladder and or into a crawl space you'll be glad you went with the lighter material.

I will definitely consider that. Good point.

**evilskillit** · **11-02-09, 07:47 PM**

I've often wondered if the vibrations from extreme bass have any visually notciable effect on projecotrs.

As long as you make a tight, manifold with the drivers firing towards eachother it seems to cancel out most of the mechanical vibration and while the bass vibrations can feel pretty extreme I'm not sure if they'd actually mess with a projector or not...

**weverb** · **11-02-09, 10:22 PM**

Quote:

ivseenbetter wrote:

1. Is there a good parts list that somebody has already built? I’m not looking for specific brands necessarily, but just a list of things I need to shop around for…obviously I need subs but I am sure there are is probably a lot of minor things like speaker wire, MDF, and other pieces that I need to start looking for.
2. I live in a Cape Cod style home which means I have deep slanting roof. I have a very long attic so there is plenty of room up there, but at the same time, I believe placement will end up having the manifold within a few inches of the roof. With one of the woofers pointed in that direction is there any concerns/issues that having this roof so close to one of the woofers cause?
3. Can a good IB system be built that will fill my room for around 1K?

Chris,

I am no expert, but I will share what I have learned installing my IB system.

1. You are going to need things like a router or jig saw, mdf & plywood or higher grade plywood for both layers, wood glue, deck screws, mounting hardware (clamps, screws, t-nuts, etc.), closed-cell weather stripping, additional dimensional lumber, jasper jig or something for cutting circles if using a router, circular saw or table saw, tie plates and paint.

2. You want as much clearance around the driver as possible. If you get closer than 2', you will need to add insulation near the driver to make it "think" it has more room. If you get closer than a foot, no amount of insulation is going to help. You are too close and the driver performance is going to suffer.

3. You can start with two Fi 18's and a Behringer EP2500 (around $1,000). That's what I started with (in a 4500+ cubic space), but added two more a few months later. For your size room, four or more Fi 18's would be best. Ideally your budget should be about $1,500.

Quote:

ivseenbetter wrote:

Would finding the best location work by running a sub in the listening position and then putting a mic up against the ceiling in the locations I am considering and then looking for the best response? If so, then it should be similar to placing a typical in room sub.

That is the basic process that you need to go through. That is exactly what I did.

Quote:

ivseenbetter wrote:

How difficult is it to attach the manifold to the ceiling joists (I believe I have 16" spacing)?

You are going to cut some additional dimensional lumber in the spot you mount the manifold. Basically creating a box. Closed-cell weather stripping will be placed on top of the box area. Your manifold will be placed on top of this, sandwiching the weather stripping creating a good seal. The manifold will then be screwed to the joist and new lumber using tie plates.

If you have more questions, let me know. I can show you my whole build process over at the Cult.

Advertisement