Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks?

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#3,345
The Nag. box is unusual. It's an expanding TL (albeit in stages), but I don't think that expansion is great enough for it to make the transition from being a 1/4 WL resonator to a 1/2 WL resonator with 1/4 wave fundamental, even though the length appears sufficient. Might not be far off. Greg's the better person to ask though.
 
#3,348
i recently did just this, building a 3 fold BIB for my fostex fe108esigma's and for a pair of monacor sp60x (i couldn't get myself to follow through with the idea of the 2 driver, tapped horn version). both pairs are awaiting suprabaffles so i can't comment about sound but hopefully it won't be too long.

here are some pics of the unfinished BIB's in my studio. as you can see the fostex pair is tiny in comparison.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


good luck with your project!

Daze said:
Hey all,

I am about to build a pair of FE166e BIBs. I do have a bit of an issue with corner placement in my room. I can’t help but think that having the speakers out into the room is more interesting for imaging. Placing the speakers flat against the wall or directly into the corners would have a negative effect on the imaging properties of my room.

I was wondering if having a 3-fold BIB (to make it twice as deep and half as tall) would have an adverse effect on the frequency ripples. The 3-folds would mean that the cabinet would be 24 inches deep and approx 8 inches wide and the mouth of the horn would be situated on both sides of the cabinet at the bottom rear (it would kind of look like the Big Fun Horn).

This BIB could be placed right in the corners of the room (and make 100% use of corner loading) and still project far enough in the room to offer good enough imaging (having the drivers away from immediate bounderies).

Please let me know if this has been tried of if you think it could have a desastrous effect on the pipe resonnance.

Thanks.
Click to expand...
 
#3,349
I don't know if others ar ehaving trouble seeing the pics giantstairs posted (looks like his picture hosting service may be blocking external links)... here is a composite of his pics.

These do give a very graphic look into what a 3-fold BIB looks like in reality. Thanx for posting those larry.

dave
 

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#3,351
thanks for that dave. i use pbase for my personal website and figured i could use it to host a few photos of the bibs.

as for the 3 fold bibs, these are a bit of an experiment so i used particle board and mdf, 1cm thick to keep the costs down. my first pair of bibs (also fe108esigma) use 18mm baltic birch and are filling my 70sq meter (750 sq foot) studio beautifully. i'm curious to hear the difference between these and the 3 fold bibs.
 
#3,352
Wow! Those are pretty much what I had in mind.

I was only going to let the horn mouth exit on both sides so I can truly cornerhorn them. This would theorically give and infinite horn (is this right?).

Is horn lenght a real issue in that case (could it be made shorter)?
 
#3,353
WOW!... I'm listening to an fe166e BiB while unit 2 is in glue-up. Played through a 2 WPC SET, fresh out of the box driver and I am impressed. I am really looking forward to hearing this setup after a proper break-in period and some tuning.
I'd like to offer a great big "Thank You !" to you guys for your selfless efforts. Cheers (and more later)!

7/10
😀
 
#3,355
Daze said:
This would theorically give and infinite horn (is this right?).

Is horn lenght a real issue in that case (could it be made shorter)?
Click to expand...

Greets!

Not infinite even theoretically since the room's dimensions sets the limits before it morphs into a parabolic flare, ultimately morphing into a sealed half WL resonator.

Yes, horns can be shortened considerably if properly corner loaded.

GM
 
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