someone suggested infinite baffle - need details

Sam A · 10-06-2004, 01:21 PM

ok in another thread, Chris Brock suggested I make my sub an IB since my GF doesnt want big speaker boxes. it would be great to hide the sub but to me, it still looks as though my sub will sound like a lowrider. also, im buying a house this week and Im really not keen on the idea of tearing up walls as soon as I get the house, but Id like the HT setup as soon as possible.

ive done my reading online and seen the IB cult pages. impressive looking subs. I guess I came to the diy section to see what help I could get keeping this as clean of a project as possible. there is a coat closet in the main room that I could use, and I could replace the door if necessary...
hmm a light bulb just went off.
ok if took the door off, and stored the door [its an older wood frame raised panel door]
then built a solid door of MDF and mounted the speakers in it, how would I make sure the door didnt rattle in the frame, I would assume I would still want to use the closet as a closet, liek those walk in freeser door handles where it really pulls the door shut. i would need a few of those.
also, how many speakers would I need? ThomasW on the IB cult site has 12 x 12"s!!!

OMG!

any thoughts ideas or corrections are very welcome

Chris Brock · 10-06-2004, 01:54 PM

Quote:

ThomasW on the IB cult site has 12 x 12"s!!!

think thomas is crazy, check out this guy!!!
http://www.geocities.com/pnwright3/Gemini_subs.html

10-06-2004, 01:59 PM

The number of drivers you can use will be partly determined by how much space you have in the closet. You typically want to shoot for a space that's 10 times larger then the VAS value of the driver. If you take the Tempest as an example then it would be 10 * 317 L per driver. So if you have 10 foot ceilings and the closet is 5 feet deep by 5 feet wide you'd be pushing it to get two tempests in that area...which for most people is a good number of drivers for a variety of reasons.

Out of curiosity what's above and below this room? Would it be possible to cut a hole in the top or bottom of the closet and cover it with a grill to increase the area available?

Rich Kraus · 10-06-2004, 08:42 PM

andrew hit it on the head, you want to take a look at the space available to vent into (closet, attic etc....) and then calculate how many drivers that space will support (in terms of 4-10X vas)

dont be afraid to cut a hole and vent in to the attic/basement. youll like the sound. its only going to boom like a low rider if you calibrate the system to be bass heavy, then play some bass heavy music.

how large if a space are you trying to add bass to, and how loud/low are you wanting your system to play?

if you want 130dB at 15Hz in an 20X30 room that opens to another room, well youd better be ready to spend some money

in my upcoming room (12x15, sealed) a pair of 15's and a few hundred watts should be enough.

if you are limiting yourself to the closet, you may find you are unable to add enough drivers to meet your bass level needs /vs room volume.

ThomasW · 10-06-2004, 10:02 PM

Closet IB's, yeap we got closet IB's. Just don't forget to cut a hole in the top of the closet, to vent the IB into the attic. Otherwise you've just got a big box sub.

There are more details of this install on page 4 of the IB gallery.

Mike Knapps line array is also a closet install with the drivers mounted on an outside wall of the closet. It too is vented to the attic

**HTF Ads**

Sam A · 10-07-2004, 12:24 PM

yeesh, well I was hoping to make the door the baffle and I guess I could cut a hole in the ceiling of the closet. Ill have to mesh the hole or something so insulation and dust doesnt fall on the clothes in the closet. what about using the hole in the ceiling of the closet as the speaker hole? would I have to keep the closet door open?

ThomasW · 10-07-2004, 01:19 PM

You can certainly flush mount the woofers in the door. People have done that, I just don't have any pictures of those installs.

There are going to be phase issues if you put the drivers in the top of the closet. As a result I don't recommend doing that.

I'm not sure how the others have addressed the hole in the top of the closet issue. Making a grill cloth is one option to keep the insulation and other stuff in place. Note that insulation can not cover the hole. There must be an unobstructed flow from the closet into that attic.

Allen Ross · 10-07-2004, 01:43 PM

Thats some serious weight to be putting on those hinges, i would be little worried about it, also getting a nice air tight seal on the door might be tricky

Sam A · 10-07-2004, 01:48 PM

Thats some serious weight to be putting on those hinges -
have you ever tried to carry a solid wood 6 panel door? ha.

also getting a nice air tight seal on the door might be tricky - thought of that - liek those walk in freeser door handles where it really pulls the door shut. i would need a few of those.. wouldnt have to be air tight, just firmly held within the frame. if I understand IB correctly, there is no comression of the air other than the sounds because there is no enclosure it must conform to, or something like that.

ThomasW · 10-07-2004, 10:28 PM

Depending on the woofers being used, one might want to consider using ball bearing hinges.

Lining any gaps with closed cell neoprene foam tape should take care of rattles