Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks? - Page 41 - diyAudio
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Old 21st April 2006, 07:56 PM   #401
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http://www.zillaspeak.com/bib-hemp.asp

Thanks Scott... this is fun!

Godzilla
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Old 21st April 2006, 08:57 PM   #402
fred76 is offline fred76  Philippines
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Hi Scott,

Forgive me, a bit OT here.. I'd try your suggestion re: enlarging driver hole for OB at extra panel behind main baffle. It would be harder since I can't remove the rear extra smaller panel (already coupled with glue n screws) of the largish baffle. But I'm curious to hear the difference. Thanks.
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Old 21st April 2006, 08:59 PM   #403
fred76 is offline fred76  Philippines
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Godzilla,

Cool 2001 images on the Monolith wide baffle Hemps.
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Old 21st April 2006, 09:14 PM   #404
fred76 is offline fred76  Philippines
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BTW, any more hints wrt stuffing/lining? Some at the throat and base of enclosure? Where else? Thanks.
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Old 21st April 2006, 11:23 PM   #405
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Nowhere until they're in position and you know what they're doing! This is one case where you really do have to stuff-to-room. I know that sounds like a cop-out, but since these use the room heavily, there's no real way of knowing beforehand. If things boom too much, try lining the second side of the sloping baffle wall (the bit that goes up to the terminus). That often works well.

Cheers
Scott
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Old 22nd April 2006, 06:04 PM   #406
fred76 is offline fred76  Philippines
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Scott,

Thanks for the tip on re: lining sloping baffle wall to terminus.

regards,
fred
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Old 22nd April 2006, 09:17 PM   #407
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Default Re: this weekend.

Quote:
Originally posted by blumenco
...........are we really even after this level of refinement, or should we even be? at what point is it more economical to build true folded horns?
Greets!

Not really, the BIB is just a simple box design to get enough gain to allow LF/midbass challenged drivers to play low without much hassle, complexity, or cost, with the major trade-off being size, so it was made tall to minimize its footprint as much as acoustically practical. Once you start tweaking it much, it's best to start from scratch with each driver.

GM
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Old 22nd April 2006, 09:25 PM   #408
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Default Re: this weekend.

Quote:
Originally posted by Scottmoose
I'd be very grateful if you could still send Jeff & myself a copy of your own sheet that you mention though Greg... I tried coming up with something in Excel myself month or so back, but I'm lousy with spreadsheets unfortunately.

Regards
Scott
Greets!

I started writing an instruction sheet and decided it would be as confusing as the WS, so began reworking it instead, but keep getting side-tracked for one reason or another.

GM
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Old 22nd April 2006, 09:36 PM   #409
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Default Re: this weekend.

Quote:
Originally posted by Dave Cigna


GM, could you elaborate little? Do you mean something other than the linear taper of a typical TQWT?
Greets!

No, in any resonant pipe regardless of taper there's an acoustic point where the driver's and pipe's resonances balance out for smoothest combined output and as it tapers from constant (straight) it moves in the direction of the taper from this point, ergo in a TQWT (reverse taper) it moves towards the closed end and for a horn (positive taper) it moves towards the mouth.

GM
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Old 22nd April 2006, 09:57 PM   #410
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Default Re: Re: this weekend.

Quote:
Originally posted by RtV
I am planning to go forward by mounting the driver into a 1" disk (like a Terry Cain cabinet) halo'ing the driver, and giving enough space for the magnet internally.

My question for the theory gurus: could this have an effect on any other dimension of the design?
Greets!

Theory and reality come together with the conclusion that as long as the 'tunnel' isn't too deep and the walls flare away at a sufficient rate to keep reflections from audibly modulating the diaphragm, then it's not an issue. Typically this means a > 20 deg chamfer and < ~3.4" deep.

GM
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