Those are all correct.
If line length is approximated (as I interpret GM's post to say it it should be) as the rough middle of the pathway then the semicircle around the base of the pathway (see post 354) takes up considerable line length (about 21 inches).
Those 21 inches should be accounted for by a reducction in your height.
Sean
If line length is approximated (as I interpret GM's post to say it it should be) as the rough middle of the pathway then the semicircle around the base of the pathway (see post 354) takes up considerable line length (about 21 inches).
Those 21 inches should be accounted for by a reducction in your height.
Sean
Hello everyone,
Been following this intresting tread for a while, and now I'm ready to try my first pair of diy speaker. The BIB looks like a fairly simple and promising unit to try.
Thanks everybody for the great investigating work on this subject.
I have a pair of fe-103 s to try out. They have been placed in cardboard box to break in for the last 3 monthes. I was originally want to put them in the bhorn2. Now i'm leaning toward the BIB.
I'm confused about the "correct" dim for the cab though. I read early on in the thread that the 103s can share the same dim as the TBs as in a 5.5 X 10.5 X 60 cab. But on Zilla's wsb site, the 103s are listed as with a line length of 85, which will translate to about 42.5 inside height, right? Which dim. should I follow.
Thanks again for everybody's great work on this subject. BTW, I made a cardboard BIB following the TBs size for 103e. The increase in spl is very noticable compare to cardboard BR they were in
If this is indicate of things then the proper built BIB 103 could be a pretty good outcome.
Tia
Have a nice weekend everyone
Lei
Been following this intresting tread for a while, and now I'm ready to try my first pair of diy speaker. The BIB looks like a fairly simple and promising unit to try.
Thanks everybody for the great investigating work on this subject.
I have a pair of fe-103 s to try out. They have been placed in cardboard box to break in for the last 3 monthes. I was originally want to put them in the bhorn2. Now i'm leaning toward the BIB.
I'm confused about the "correct" dim for the cab though. I read early on in the thread that the 103s can share the same dim as the TBs as in a 5.5 X 10.5 X 60 cab. But on Zilla's wsb site, the 103s are listed as with a line length of 85, which will translate to about 42.5 inside height, right? Which dim. should I follow.
Thanks again for everybody's great work on this subject. BTW, I made a cardboard BIB following the TBs size for 103e. The increase in spl is very noticable compare to cardboard BR they were in
If this is indicate of things then the proper built BIB 103 could be a pretty good outcome. Tia
Have a nice weekend everyone
Lei
Am I going mad or have I seen this post before 2 pages back? Machines.
To repeat what 'Zilla said before: ignore the first lot of dims you cite and use the dimensions now available on his site with the 85in length. Too long a horn and you'll tune the driver too low and the mid-bass will vanish.
Best
Scott
Oh yes -and happy Easter to all!
To repeat what 'Zilla said before: ignore the first lot of dims you cite and use the dimensions now available on his site with the 85in length. Too long a horn and you'll tune the driver too low and the mid-bass will vanish.
Best
Scott
Oh yes -and happy Easter to all!
The line length is equal to the speaker enclosure height multiplied by two. Lets say your BIB has a L of 144 inches. Your BIB is 72 inches tall. It is divided by the sloping internal panel.
Thats it.
L = from the top of the speaker box to the bottom of the speaker box and back up to the top of the speaker box, hence height multiplied by two in this case 72" X 2.
Andrew
Thats it.
L = from the top of the speaker box to the bottom of the speaker box and back up to the top of the speaker box, hence height multiplied by two in this case 72" X 2.
Andrew
Andrewbee said:
This is close enought to be true in most BIBs. BIBs with excessive depth relative to line length (WAG Depth > 1/5 line length) generate a path length that is slightly shorter than expected using this rule of thumb.
Curved path length around Fold is shorter than vertical measurement (pi*D/4 versus D)
Angled path from curved path around fold to throat and angled path from curved path around fold are identical in length and are marginally longer than vertical path.
When depth is reasonable these factors nearly balance out. When Sm gets huge and you decide to do a 2-3 foot deep BIB that is ~6 feet tall you might get errors of 2-3 inches in height that will tune the horn a little higher in frequency.
Whether this makes any difference in the end, it probably doesn't.
Sean
loninappleton said:
Greets!
Well, my 'knee jerk' response is.......either buy Oak or Poplar stock or a saw and some no-void plywood.
The vast majority of projects I've built had butt joints and most I blind screwed them together using homemade clamps and drilling jigs when there was enough room to do so (I grew up around some master woodworkers that refused to own power tools). You can now buy nice kits marketed as 'pocket hole' to do the same thing. Obviously, when there's not enough room you have to either screw along the edges (bad plan) or use screw blocks per Weems, et al.
Anyway, you orient the wood so it bows inward in the middle and start screwing it together at one end, working your way to the other, bending as you go. Twisted wood requires you to orient them so that they oppose each other so that they are in tension.
GM
Scottmoose said:
Greets!
I wish! It's really bad now. Anyway, As I implied, a SO = 0 design requires the driver be located further down with increasing taper ratio for smoothest response, but with the BIB design we're more interested in gain/BW, so it's a balance thing where we're 'shooting blind' to some extent since without hard data to see the room's effect, all we can do is make a semi-educated guess.
GM
fred76 said:
Greets!
Happy Easter to you too!
Judging by all the stores open and having sales around here the only thing being celebrated was the Almighty Dollar. Anyway, in re-reading my response, I inadvertantly implied that both drivers use the same design, but not quite true, the specs I posted are for the 165GMF and the 165LB is the same except has a 300"^2 mouth to get ~the same response, and since they are so much larger than the currently posted design, they will have far more gain overall.
GM
seanzozo said:
Greets!
You beat me to it.
Anyway, at a glance it looks like you didn't account for the internal baffle's thickness. Anyway, thanks for sharing, the one I made for doing horns, etc., that I was going to send Scott and Jeff isn't elaborate enough for general use. WRT accuracy, line length isn't all that critical per se, but net Vb and mouth area is, so we want to err on the large or too long side IMO since most of the drivers contemplated have to rely solely on box efficiency/room gain for the BW below a few hundred Hz..
GM
this weekend.
I have built the cabinets, need to cut the bases, need to sand, then finish.
they are huge!!! very heavy. the bases will be double thick and trapezoidal in shape. I am going to put some 9 inch wide panels on either side of the cabinet to extend the baffle. give the sound a little more body.
I kept the reccommended dims exact on these. using 6 hp sound reflectors in each cabinet, and using very small 45 degree angled peices of alder for added strength in key places. I regret not trying the multi layered and stepped back panel to give the horn more shape, but i think it will be fine just like it is.
furthermore, I have had an idea for the internal dimentions and wood cutting, etc. instead of an angled panel, one would step almost all the panels into a shape of an internal baffle. this would keep internal panels parallel to the front and back, while giving more of a horn shape to the things. incriments would be more or less 3/4 inch. kinda like the fostex blh stuff. way more complecated though. the benifit though is that without a mitre, it could be done relatively easily. very strong no doubt. it would also be possible to bring more of a throat to the horn, if that is desirable. more of a mouth to the horn. easy to create internal sections filled with sand. no doubt, these style of cabinets might be much bigger to fit this horn shape and construction method. maybe like 33 percent added to the depth versus normal angled panel. bigger is better? R and D would be daunting. each driver would have to be revisited over and over. for some of the fostex stuff that is kindof like an institution, like the 103, 166, 127, 168, it would be easier. many people build these it seems. mid bass optimization would be more promising though perhaps (?) this is what y'all have been talking about though. this truncated business (?) who will develop it? 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?
one other thing--when simming cabinets from now on, y'all might want to put in a little part about magnet clearance. I ended up with 1/16 too little. chamfering out a peice of the internal baffle to fit. no biggie. just a little less elegant than I was hoping. i guess the 166es-rs are a little strange and uncommon in that realm though. huge huge magnet for the driver size. most of the dimensions with different drivers though are pretty close. I know that the dimentions give room to play with width/depth, and that it might be noted to consider for magnet size.
I have pictorally documented almost all of the construction process. If it needs to go into a fun little instructional section, then i will post it all with commentary. I am no horn expert, or expert woodworker. I have been using relatively rudimentary tools as well, so that might help the newbies who really want to build but are a hair scared or think themselves undertooled or poor.
well, pictures are coming soon.
it was a fun weekend, thanks for the dimentions.
Clark
I have built the cabinets, need to cut the bases, need to sand, then finish.
they are huge!!! very heavy. the bases will be double thick and trapezoidal in shape. I am going to put some 9 inch wide panels on either side of the cabinet to extend the baffle. give the sound a little more body.
I kept the reccommended dims exact on these. using 6 hp sound reflectors in each cabinet, and using very small 45 degree angled peices of alder for added strength in key places. I regret not trying the multi layered and stepped back panel to give the horn more shape, but i think it will be fine just like it is.
furthermore, I have had an idea for the internal dimentions and wood cutting, etc. instead of an angled panel, one would step almost all the panels into a shape of an internal baffle. this would keep internal panels parallel to the front and back, while giving more of a horn shape to the things. incriments would be more or less 3/4 inch. kinda like the fostex blh stuff. way more complecated though. the benifit though is that without a mitre, it could be done relatively easily. very strong no doubt. it would also be possible to bring more of a throat to the horn, if that is desirable. more of a mouth to the horn. easy to create internal sections filled with sand. no doubt, these style of cabinets might be much bigger to fit this horn shape and construction method. maybe like 33 percent added to the depth versus normal angled panel. bigger is better? R and D would be daunting. each driver would have to be revisited over and over. for some of the fostex stuff that is kindof like an institution, like the 103, 166, 127, 168, it would be easier. many people build these it seems. mid bass optimization would be more promising though perhaps (?) this is what y'all have been talking about though. this truncated business (?) who will develop it? 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?
one other thing--when simming cabinets from now on, y'all might want to put in a little part about magnet clearance. I ended up with 1/16 too little. chamfering out a peice of the internal baffle to fit. no biggie. just a little less elegant than I was hoping. i guess the 166es-rs are a little strange and uncommon in that realm though. huge huge magnet for the driver size. most of the dimensions with different drivers though are pretty close. I know that the dimentions give room to play with width/depth, and that it might be noted to consider for magnet size.
I have pictorally documented almost all of the construction process. If it needs to go into a fun little instructional section, then i will post it all with commentary. I am no horn expert, or expert woodworker. I have been using relatively rudimentary tools as well, so that might help the newbies who really want to build but are a hair scared or think themselves undertooled or poor.
well, pictures are coming soon.
it was a fun weekend, thanks for the dimentions.
Clark
Re: this weekend.
Clark,
Congratulations! Looking forward to the pics and your first listening impressions.
As for magnet clearance. After I made up some detailed drawings of the recommended dims for the 108ES, it was very clear that there would be no way to get it into the available space at 17.5" from S0.
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?
Thanks,
Randy
blumenco said:
Clark,
Congratulations! Looking forward to the pics and your first listening impressions.
As for magnet clearance. After I made up some detailed drawings of the recommended dims for the 108ES, it was very clear that there would be no way to get it into the available space at 17.5" from S0.
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?
Thanks,
Randy
Greets!
A quick note......
Since the object of this thread and it's associated webpages are to address as many aspects of BIB design as practical, I'm not going to respond to any more private emails on this subject from anyone except Scott or Jeff, so any unanswered Qs need to be posted here and eventually someone will answer them.
GM
A quick note......
Since the object of this thread and it's associated webpages are to address as many aspects of BIB design as practical, I'm not going to respond to any more private emails on this subject from anyone except Scott or Jeff, so any unanswered Qs need to be posted here and eventually someone will answer them.
GM
I take it you were being inundated then Greg?
Randy -sounds like a good plan to me. That's one of the difficulties of the sizing unfortunately. The disk is a good idea to give the extra clearence -just remember to rout out the rear of that, and enlarge the hole in the front baffle to let the driver breath properly. Will it affect other aspects? Well, it'll affect baffle-step, but that should be fairly negligable anyway if the enclosures are positioned as they are designed to be -pushed right back into corners or against a rear wall. It shouldn't do anything to the rest though. Side beneft will probably occur in damping any front-panel resonance. There are different views as to the advisability of different shapes of false baffle. Not something I know enough about to pass comment. GM suggested an asymmetrical shape elsewhere. TC still favours circular, especially when provided with a constantly varying surface (and they appear to work beautifully on his own speakers), Bob Brines, a sort of Zulu-sheild form, others a rectangular shape. Room for experiment I think! Not something I've played with much.
Best
Scott
Randy -sounds like a good plan to me. That's one of the difficulties of the sizing unfortunately. The disk is a good idea to give the extra clearence -just remember to rout out the rear of that, and enlarge the hole in the front baffle to let the driver breath properly. Will it affect other aspects? Well, it'll affect baffle-step, but that should be fairly negligable anyway if the enclosures are positioned as they are designed to be -pushed right back into corners or against a rear wall. It shouldn't do anything to the rest though. Side beneft will probably occur in damping any front-panel resonance. There are different views as to the advisability of different shapes of false baffle. Not something I know enough about to pass comment. GM suggested an asymmetrical shape elsewhere. TC still favours circular, especially when provided with a constantly varying surface (and they appear to work beautifully on his own speakers), Bob Brines, a sort of Zulu-sheild form, others a rectangular shape. Room for experiment I think! Not something I've played with much.
Best
Scott
It just occurred to me that the BIB does pose interesting and unique problems for the false baffle, since the speaker is meant to be placed in the corner.
An asymmetrical baffle makes sense in this context, given the proximity of the side wall. But this might also depend on whether the speakers are toed in at all. And who would know until the speakers are broken in and you start experimenting with placement? Catch 22.
Randy
An asymmetrical baffle makes sense in this context, given the proximity of the side wall. But this might also depend on whether the speakers are toed in at all. And who would know until the speakers are broken in and you start experimenting with placement? Catch 22.
Randy
Of course. That's part of the fun, so to speak. This enclosure is not the most predictable in the world anyway as they use the room much more than many other types. To be honest, I reckon that the differences will be fairly small, so it's probably best to rough a few baffle ideas up, then when you've got the one you like most, build a finalised version. That said, I gather that the podular baffles a la C&C do work very well, right Dan? I keep meaning to try it, but hardwoods are a pain to come by in my neck of the woods, and if you do find a supplier, you're unlikely to be able to see the stuff before purchace. And then you need to find a tame wood-shop with a lathe. Again, not easy around Hull.
http://img414.imageshack.us/my.php?image=tqwt18zh.jpg
perhaps here's a way to invert the BIB design?
perhaps here's a way to invert the BIB design?