ultimate DIY sub LOL (1 Viewer)

[Greg Kolinski]

I saw this in a "home theater "type mag years ago,cant remember the name .But this guy was truely insane ,one of those "if I get that bad, I'll. stop" .Anyway this guy built a rack of something like 10-12 15 in drivers,about 6 feet high,all powered ,in his basement in a small room.Then cut a hole in the floor in his living room for a port?and user the small room as the encloser. From the way the article talked this thing was slowly destroying the structual integrity of the house windows loose etc.Does antone else remember this?I was just starting to get interested in this hobby then,shoot it was before basic Pro-logic I think,cause I remember my AVR" then only had 15 watts to the rears ,and no center.I hope someone remembers this cause it was truelty insane,I my be wrong on some of the specs ,etc,but the part I remember the most was the basement ,and the hole in the living room floor.This guy was my personal hero for many years for his great undrtaking

Greg

 

[Johnny Garvin]

I believe you are refering to the the June 1999 issue of S&V. In that issue there was an article by Tom Nousaine called "the subwoofer that shook the world." He built an IB subwoofer in his basement that ported into his theater room. When I first read it, I was really intrigued by the idea. About several months ago,I was finally able to build one. It's a little more modest though; I only have 2 12" drivers for mine The bass quality is absolutely incredible!! You have to hear an IB to really understand what I'm trying to describe.
The bass has wonderful clarity and detail. It hits hard and fast when it should. I will NEVER go back to a traditional box sub again. The bass quality from an IB sub is VERY addicting. Smooth,clean, deep and fast. There is a wonderful forum dedicated to the IB subwoofer that would give you a better understanding of it.http://f20.parsimony.net/forum.36475/index.htm
I can email you a copy of the article if you would like to read it again. Remember: IB subwoofer = bass nirvana

 

[Dustin B]

Check out the gallery in the link Johnny provided. You'll have many more heros. I hope to eventually do a four 15" driver IB in my attic myself.

IB's if you have an appropriate adjacent space, IB subs have so many pluses. One of, if not the, easiest DIY subs to build. Excellent sound quality. Very cheap relative to the performance you get (this depends a little on the drivers you choose). Takes up zero space in your room. Requires very little power since the drivers are basically opperating free air.

Johnny, if you have that article please email me a copy. I'd like to read it.

 

[Greg Kolinski]

Johnny.......YES,please email me the article.I had been looking for the magizine but appartly have lost it

[email protected]

thanks
greg

 

[Brian Bunge]

Dustin,

The only thing that's possibly more simple would be a dipole sub!

 

[Dustin B]

Well, except the dipole should still be finished and cut cleanily. You can do a really rough box and not have to worry about the finish on an IB.

So it depends on what you fear more, box construction or finishing. And since I don't do enough wood work to be good at finishing, well you get the idea.

I really don't know how I'm gonna manage sealed HE12.1 in a triangle shaped tower with the equipment and skills I have

 

[Jack Keck]

I tried this link and all I got was a site where all the words were funny. I coudn't make heads or tails out of it. BTW, I remember teh Nousaine article and found it fascinating.

 

[Dustin B]

http://www.f20.parsimony.net/forum36475/

Try this one.

 

[Johnny Garvin]

I'll email you both a copy of the article as soon as I scan it today. Jack, sorry for the link. I forgot to put the "www" in front of it.

 

[Haru]

could I get a copy too please? my email address

 

[Haru]

guys,

I have a pair of car subs that I never installed. It is the model Coustic DR-330, essentially two 10" drivers mounted face to face, and venting through a hole to the side. I have two of these. I installed one in my car but never wired it up, and the other one sits in its unopened box.

seems to me that these are perfect infinite baffle subs, just waiting to be installed, needing nothing more than a port. I was going to give them away, but I guess I'll hold onto them till there is an opportunity for me to put them to use. my existing 2 x 2 x 12" sealed sub-woofage means I don't have to do anything about it right away.....

although, I must admit that I am confused. when I bought these subs 3-4 years ago, they were already out of production and I was trying to find out about this type and the universal consensus from experts was quite negative. Its been too long for me to remember what the problem was, but it was one or both of the following.

1. interaction between the air masses on either side of the driver cone was not precisely engineered.

2. the airmass behind the drivers provided no "spring", no resistance to the cone's movement, thus causing the sub to rely only on its suspension for control, and that suspension that would provide adequate control would be very stiff and require huge amounts of power......

please treat this with the skepticism that 3-4 year old, out-of-inexpert-memory should be treated with.

 

[Dustin B]

They don't provide any T/S specs, so there is no way to tell how suited those 10" drivers are to IB use. I doubt they have anywhere near the Vd required for use in a room and I'd bet their Fs is too high.

For point 1, the point of an IB is that it is an infinite baffle. An infinite baffle, is well infinite and won't allow the front and back waves to interact. So as long as the space on either side of the driver is large enough, the driver will behave like it is in free air, but since the front and back waves are isolated there will be no cancelation of the bass.

For point2, again, the point of an IB, to get the driver operating free air so the spring can't affect the sound. The Qts then becomes the system Q of sub. Below 0.5 is over damped, 0.5 is critically damped and over 0.5 is under damped. The preferred range would be some where between 0.5 and 0.707. Although many people seem to be very happy with 0.4 in an IB setup.

IB subs are also more or less always mechanically limited, not power limited (thermal limits), as they require much less power to reach their drivers Xmax since they are operating free air.

 

[AndyHangartner]

The one downside to the IB is the lack of 'punch'. I have a setup with four PE dayton IB 12's and although it is smooth and accurate, you don't have the 'punch' normally caused by a peak somewhere in the curve that gives the impact feeling.This will give the feeling of not enough bass,and it is a little disheartening at times.The answer at this point is a multi-selectable eq like the Feedback destroyer so you can setup a number of different curves.
my .02
andy

 

[Johnny Garvin]

guys, I have the article scanned but I think it is a bit large. It's about 6mb. I would like to get it down to a smaller size if possible. Any suggestions would be appreciated. I can send it like it is, if the size doesn't bother you. Let me know.

Andy, you're right the IB doesn't have the "punch" that you get from a box sub. It's like you said the IB is more linear over its response curve therefore you don't get the peak that you would from a traditional box sub. It really does takes time to adjust to the bass output of an infinite baffle. Movies that had smoking bass with your box sub don't sound quite as impressive with an IB. Now mind you ,on those outstanding demo movies(LOTR,Star Wars 1&2,TS2 etc.)my IB brings the house down in wonderful fashion. OH MY!!!

It takes some time to get acclimated to the smoothness and accurateness of an infinite baffle, but once you do NOTHING else will satisfy you.
I LOVE MY IB!!!

 

[Gabriel_Lam]

Slightly different, but anyone remember this one?

Sub Horn

 

[Brian Bunge]

Gabriel,

Oh, that little thing? Yeah, I remember it.