I have a Tangband W4-657SH 4" driver I'd like to put in a BIB. However, I would rather have something shorter than the 51.75 inches that the BIB calculator calls for- bib-calculator. Yet I would still kilke it to be a floor standing speaker.
How would I effectively cut that in half so I have a shorter "BIB?"
I'm thinking that if I keep the line the same length, the volume the same, and put the mouth at the bottom rear it would effectively be the same as a standard BIB for this particular driver. The issue I haven't settled thus far is the spacing above what would be the apex, the bend in the line.
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This is a rough aasci drawing of how I think it might look. The x's are where the speaker would go and the blank bottom right corner would be the mouth. Would the apex have equal dimensions from the front, back, and top? And my thought is that it would be twice as deep as if it weren't cut in half.
Does this make sense?
I'd like to try something with a single driver that's a little "outside the typical monkey coffin-type box."
Here are the T/S parameters for this driver:
Specifications: Power Handling: 30 watts RMS/60 watts max *VCdia: 1" *Znom: 8 ohms *Re: 6.0 ohms *Frequency range: 65-16,000 Hz *Fs: 65 Hz *SPL: 88 dB 1W/1m *Vas: .22 cu. ft. *Qms: 3.32 *Qes: .43 *Qts: .38 *Xmax: 3 mm *Dimensions: A: 4-15/16", B: 3-3/4", C: 2-7/8".
Thanks,
Mike
How would I effectively cut that in half so I have a shorter "BIB?"
I'm thinking that if I keep the line the same length, the volume the same, and put the mouth at the bottom rear it would effectively be the same as a standard BIB for this particular driver. The issue I haven't settled thus far is the spacing above what would be the apex, the bend in the line.
__________
|................|
x................|
x......./\.......|
|....../..\ …...|
|...../....\.....|
|..../......\....|
|.../........\...|
|../..........\
|./............\
|/..............\
This is a rough aasci drawing of how I think it might look. The x's are where the speaker would go and the blank bottom right corner would be the mouth. Would the apex have equal dimensions from the front, back, and top? And my thought is that it would be twice as deep as if it weren't cut in half.
Does this make sense?
I'd like to try something with a single driver that's a little "outside the typical monkey coffin-type box."
Here are the T/S parameters for this driver:
Specifications: Power Handling: 30 watts RMS/60 watts max *VCdia: 1" *Znom: 8 ohms *Re: 6.0 ohms *Frequency range: 65-16,000 Hz *Fs: 65 Hz *SPL: 88 dB 1W/1m *Vas: .22 cu. ft. *Qms: 3.32 *Qes: .43 *Qts: .38 *Xmax: 3 mm *Dimensions: A: 4-15/16", B: 3-3/4", C: 2-7/8".
Thanks,
Mike
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Bigger Is Better 'BIB' Cabinet Dimensions - ZillaSpeak.com
Here is something not many have pursued yet...
Godzilla
Here is something not many have pursued yet...
Godzilla
Certainly people have done 2 fold BIBs, 3 folds would be easier to fit into a rectangular box.
dave
Edit: i see Zilla beat me to the punch. Without doing any work, i'm going to guess that his 3-fold has 2 distinct sections with different taper -- probably not a big deal.
dave
Edit: i see Zilla beat me to the punch. Without doing any work, i'm going to guess that his 3-fold has 2 distinct sections with different taper -- probably not a big deal.
The big problem is driver height referenced to listening height.............
51.75"/3 = 17.25" i.d., but the driver is supposed to be at ~11.12" i.d., so near enough to the floor to make floor bounce a major concern if the baffle's not angled back fairly steeply, screwing up the fold layout.
GM
51.75"/3 = 17.25" i.d., but the driver is supposed to be at ~11.12" i.d., so near enough to the floor to make floor bounce a major concern if the baffle's not angled back fairly steeply, screwing up the fold layout.
GM
Does this look like it might work?
I divided the line (103.5 inches) by three = 34.5. So the height would be approximately 38 inches (I centered the line between the baffle and the top of the cabinet).
The driver could stay at approximately 29.25 inches from the floor (the distance the calculator provided for the standard BIB for this driver).
The mouth on the upper rear would be approximately 7.75 inches by 5.5 inches (I.D).
Am I in the ballpark?
Thanks for sharing your expertise!
Mike
OOPS... I see Zilla posted what I'm looking for.
I divided the line (103.5 inches) by three = 34.5. So the height would be approximately 38 inches (I centered the line between the baffle and the top of the cabinet).
The driver could stay at approximately 29.25 inches from the floor (the distance the calculator provided for the standard BIB for this driver).
The mouth on the upper rear would be approximately 7.75 inches by 5.5 inches (I.D).
Am I in the ballpark?
Thanks for sharing your expertise!
Mike
OOPS... I see Zilla posted what I'm looking for.
Attachments
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Oops too! I thought the total line length was 51.75".
Regardless, you'll need to take G's layout and turn it upside down to get the mouth floor loaded otherwise the driver will bottom out/blow up at very low SPLs if it 'feels' any low notes.
GM
Regardless, you'll need to take G's layout and turn it upside down to get the mouth floor loaded otherwise the driver will bottom out/blow up at very low SPLs if it 'feels' any low notes.
GM
twice the depth, half the height
as drawn above (both of mikje's drawings but not zilla's) the line length is not nearly the same and the expansion is not conserved.
with 4 folds everything works, although driver height is a bit low. You could also have it exit at the floor, spaced up with feet or spikes. Lots of good bass with this layout.
The 3 fold version looks interesting, although not tall enough to couple to most ceilings. oops, GM explained that above.
as drawn above (both of mikje's drawings but not zilla's) the line length is not nearly the same and the expansion is not conserved.
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.
with 4 folds everything works, although driver height is a bit low. You could also have it exit at the floor, spaced up with feet or spikes. Lots of good bass with this layout.
The 3 fold version looks interesting, although not tall enough to couple to most ceilings. oops, GM explained that above.
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Wow Gainstairs! I really love the 'four fold' BIB! Thanks for sharing your pics! Can i post them onto the BIB site? Half the height and twice the depth might work really well for many... and corner loaded the sense of space and image size might be similar to a regular BIB... perhaps even better? All those 80" tall BIBs could be cut down to 40" and maybe around 20" depth fit into tight spaces next to wall units already jutting out 20" or more without the height that could dominate a room. Very cool!
Godzilla
Godzilla
If the slants in my drawing are right around 34 inches, that would give me a total of three 34 inch surfaces of "line travel," equaling 102 inches. Zilla's calculator calls for 103 inches. Am I figuring this correctly?
As far as conserving the expansion, if I made the rear baffle parallel to the rear-most slant, would that work?
Question/advice time...The more I look into this, the more I can't help but think that maybe I should stick with a "traditional" BIB. It's tried and true, and I'm definitely not versed in the dynamics/physics/magic of speaker design- especially this type of enclosure.
At any rate, I want a floor stander that's attractive and not huge. The height of this driver's BIB, in it's traditional form, is right around the 5 foot mark. If it works like my drawing, it would be around 40 inches tall. Either would work. Whatever direction I go, I want it to SOUND good, most importantly.
Thanks for the input and patience,
Mike
As far as conserving the expansion, if I made the rear baffle parallel to the rear-most slant, would that work?
Question/advice time...The more I look into this, the more I can't help but think that maybe I should stick with a "traditional" BIB. It's tried and true, and I'm definitely not versed in the dynamics/physics/magic of speaker design- especially this type of enclosure.
At any rate, I want a floor stander that's attractive and not huge. The height of this driver's BIB, in it's traditional form, is right around the 5 foot mark. If it works like my drawing, it would be around 40 inches tall. Either would work. Whatever direction I go, I want it to SOUND good, most importantly.
Thanks for the input and patience,
Mike
Attachments
As drawn, you have a fast initial expansion then the second fold has little/none and the final expansion is a reverse one, so in essence you have a high performance muffler like often used on motorcycles, though theirs are usually round. If you space the back board out is going in the right direction, but there's still the problem of the second section not expanding plus now there's the problem of getting good boundary loading of the mouth, so basically a seriously flawed design as BIBs go.
GM
GM
GM,
Thanks for the explanation. I think I'm starting to get my mind around the expansion concept, but just barely.
This gives me a lot more to think about... learning is taking place!
Thanks again,
Mike
Thanks for the explanation. I think I'm starting to get my mind around the expansion concept, but just barely.
This gives me a lot more to think about... learning is taking place!
Thanks again,
Mike
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