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

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#3,142
peterbrorsson said:

Thanks for reply!

So the dip will roughly be around 90-100Hz?

Most women look pretty smooth after 7 beers also

Some people in Germany rave about the sound from them, but as always???
Click to expand...

Greets!

You're welcome!

Not necessarily, how much the pipe loads the driver will determine how much it shifts upward in frequency from the theoretical simple calc.

Yeah, they do get prettier viewed through the bottom of a Jose Cuervo bottle or at closing time, or so some country songs claim, but I never waited that long. 😉

Yeah, as always.......... a plot that good usually is either excessively smoothed or so well damped it sounds dull. Either way, as a general rule a low XO point and/or steep slope is required for best performance.

GM
 
#3,143

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#3,144
OK Dave,

The BIB SD12 is a little over the top!! I love it. It's too tall to fit into my room, but I'm imagining laying it on its side and making a entertainment console. Heck you could lay some Frugel horns on their sides on the top of it, and have a monster 50's console.

Chris
 
#3,147
isn't this subwoofer nothing but a (very big) folded Voigt pipe ?

isn't the BiB nothing but a big folded Voigt pipe ?

But as a Voigt pipe is a Tapped Quarter Wave Pipe,
and a BiB is calculated using half the wave,
the BiB is a Tapped Half Wave Pipe ?

:smash: THWP :smash:
 
#3,148

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#3,149
Empee said:
isn't this subwoofer nothing but a (very big) folded Voigt pipe ?
isn't the BiB nothing but a big folded Voigt pipe ?
But as a Voigt pipe is a Tapped Quarter Wave Pipe,
and a BiB is calculated using half the wave,
the BiB is a Tapped Half Wave Pipe ?
:smash: THWP :smash:
Click to expand...

Neither are tapped. A tapped horn has the driver mounted through the internal baffle. In a sense you're right though: these are pipe-horns, and in most respects are far closer to P.G.A.H. Voigt's original patent than any of the so-called 'Voigt Pipes' ever were. Re the half wave, we have to be careful here not to confuse a half-wave resonator with 1/2 wave tuning.

A half-wave resonator is a pipe open at both ends. A 1/4 wave resonator is a pipe sealed at one end. Therefore, these pipe-horns are not half-wave resonators, but tapered 1/4 wave resonators that are 1/2 wavelength tuned, i.e 1/2 wavelength of the target Fc is used to set line length, as you observe.
 
#3,150
Empee said:
isn't this subwoofer nothing but a (very big) folded Voigt pipe ?

isn't the BiB nothing but a big folded Voigt pipe ?

But as a Voigt pipe is a Tapped Quarter Wave Pipe,
and a BiB is calculated using half the wave,
the BiB is a Tapped Half Wave Pipe ?
Click to expand...

Greets!

Correct.

Yes.

Just as a Leopard can't change its spots, a TQWP can't change its fundamental resonance. A BIB alignment is just a 1/4 WL of Fs/2, though there's a number of low Fs driver designs posted that are tuned around Fs to keep its size and/or driver location semi-acceptable.

BTW, the BIB is a horn due to its positive expansion, a TQWP is the opposite, a reverse tapered horn.

GM
 
#3,152
Scottmoose said:

Neither are tapped. A tapped horn has the driver mounted through the internal baffle.
Click to expand...

Greets!

I started to say this, but decided that the fact that DSL chooses to use the term 'tapped' to define its pipe horn loading technique doesn't change the fact that any TL, MLTL, horn, TQWP with the driver offset along its length is a tapped one.

GM
 
#3,157
Hello from Florida...

The reason I ask is attached.....I just finished these a couple of weeks ago after reading the first half of this thread. 84" tall-FE206e-wrapped in speaker cloth. After 23 years of maggies, I feel like I just made giant center channel speakers. I've been wondering about anding more drivers without calling it an array.
Would sealing one driver and then allowing the other the proper line length give a coherent soundstage? Bi-wired? These questions and more........Less than two months reading this thread and visiting your sites and homes in pictures and I feel like
I can build anything.....thanks.
 
#3,158
Re: Hello from Florida...

edgebc said:
The reason I ask is attached.....I just finished these a couple of weeks ago after reading the first half of this thread. 84" tall-FE206e-wrapped in speaker cloth. After 23 years of maggies, I feel like I just made giant center channel speakers. I've been wondering about anding more drivers without calling it an array.
Would sealing one driver and then allowing the other the proper line length give a coherent soundstage? Bi-wired? These questions and more........Less than two months reading this thread and visiting your sites and homes in pictures and I feel like
I can build anything.....thanks.
Click to expand...

Where is the picture? 🙂
 
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