oh. i could have never imagined that BiB's top needs to be that close to the ceiling. all the while i was thinking to let the terminus have some breathing space! 
i didnt quite get how the 'tophat' looks but i think all that you meant was to add a extension tube. i think a thick pvc pipe will do with the leaks at four corners sealed
i didnt quite get how the 'tophat' looks but i think all that you meant was to add a extension tube. i think a thick pvc pipe will do with the leaks at four corners sealed
It's literally just an extension of the basic rectangular BIB perched on top with some way to gasket/firmly attach it. If a smaller area pipe were used it would be tuned lower than the tophat, which is already pretty much at the limit below Fs this driver's specs will tolerate: [56 Hz*0.59 Qts]/2 = 16.52 Hz Vs the tophat's ~18 Hz.
GM
GM
At this point, is a community favorite BIB horn/driver combo becoming clear? My mentor Terry Cain was developing a few different BIB horn concepts towards the end of his life. But first before sharing those designs I am curious what direction the community has gone during these years since his untimely passing. Apparently, many directions have been tried! But.. catching up on the many, many pages of threads is daunting... I am just asking for a few favorites... a few "best of's" To save me from having to try a million new drivers out!
-Clark
-Clark
I dot't know the answer, but I guess that an fullrange 6.5 " driver would be closest to the best choice for this design, and that Terry would be proud to see this thread still going strong in 2018, with hundreds of pages, enough for a dedicated book about BiB
@clark,
I have only built and listened to one pair of BIBs, but I can say that the Alpair 10.3 seems to work very well. My A10.3 BIBs give me a flat octave from 25 to 50 Hz in my room, something I have never seen from any of my other speakers. Perhaps this is due to the horn mouth being only 7.75" from the ceiling. The result is excellent concert hall type bass--not chest thumping club type bass. Since my interest is in classical and jazz, this works for me. As always: YMMV.
I have only built and listened to one pair of BIBs, but I can say that the Alpair 10.3 seems to work very well. My A10.3 BIBs give me a flat octave from 25 to 50 Hz in my room, something I have never seen from any of my other speakers. Perhaps this is due to the horn mouth being only 7.75" from the ceiling. The result is excellent concert hall type bass--not chest thumping club type bass. Since my interest is in classical and jazz, this works for me. As always: YMMV.
Doesn't appear to be beyond small[er] 'FR' drivers, but 'best of', I've no clue, especially since so many different sizes, specs have been built or at least simmed, though from a technical POV, higher Qt drivers [max ~0.707 Qts'] with an Fs/2 that puts the terminus near the ceiling or driver at an appropriate ear height if inverted for floor loading would be prime considerations.
Qts' = Qts + any added series resistance [Rs]: mh-audio.nl - Home
GM
A very special BiB
Time to say THANKS!!!
I haven't been building loudspeakers for 30 years (as a 20year old newb), but when moving to our new appartement I wanted to give it a try. The hearing room is somewhat special concerning it is a roof chamber with three different pitches of the roof, a door at the back wall hindering a symmetrical speaker placement and a pillar in the middle of the room. That's when I stumbled upon this MEGA-thread and was instantly infected with the idea that a speaker loading into the ceiling could be optimal for this kind of room. So I read through the whole (!) thread and that was quite an enlightenment: So many nice people, so many interesting ideas!!! My main problem: Corner placement was not possible because of other furniture that could not be placed elsewhere and for placement at least near a wall the maximal height of the speaker would be 120 cm (47.2") because of the droop going that far down => Not quite a BiB in the common sense! I didn't need a bass down to 30 Hz or so cause I have a dedicated Subwoofer, so I ran the BiB Calculator with some Full Range Speakers, but they didn't quite fit the bill. The speakers were all too tall and slim, mainly because of fs beeing too low for my special case. So I switched to musician/PA coax speakers and found some that came quite near, the best but also the most expensive (for my budget far too expensive) being the BMS 8CN552 (fs = 87.6 Hz, Qts = 0.29, Vas = 10.08 l / 0.356 ft3). That also correlated with my musical habits hearing mostly dub/electronic music at sometimes quite loud levels. What a lucky coincidence that a few weeks later I found (and was able to pick up) a quasi new pair of these exact speakers on ebay for half the price! So I did some further simulations with Martin J Kings spreadsheets and these are the (inner) dimensions I ended up with (because of cosmetical and practical considerations there are some small deviations to the results from the BiB calculator, but the simulations were rather promising):
Height: 117.8 cm / 46.4"
Width: 19.6 cm / 7.7"
Depth: 33.7 cm / 13.3"
Z driver: 45 cm / 17.7"
The housings are made of the best birch ply I could find here in Germany (not so easy and quite expensive) in 18 mm (0.7"). The internal divider is made of 19 mm (0.75") MDF. Because the depth of the speakers was to big for this enclosure I needed a supra baffle and they are the very fine work of a local wood turner (made of alder). Side note: I love frisbees and a frisbee was the model for th wood turner! As you can see in the photos I rasped out the back of the supra baffle to give the speakers more room to breathe as was suggested in this thread. As far as damping is concerned I lined up the front side of the internal divider and the front part of the side walls from the tip down to a bit below the speaker (sorry, can't remember what kind of material that was) and two layers of rock wool on the ground. I also made a frame with some speaker cloth for the top (mainly to not collect dust or childrens toys in the cabinets). The finish is three layers of slightly coloured (mainly to emphasize the contrast between alder and birch) oil wax and a final layer of a glossy clear oil wax. I'm very content with the look of the speakers!
Now to the most important, the sound: I use a miniDSP for the crossovers and the room correction. I made some measurements with REW and after the first iterations I didn't feel any need to further fiddle around with measurements and DSP settings, I just wanted to enjoy the sound. I have not much experience with high end speakers but these ones for me have it all! The bass even without the subwoofer goes quite deep (at least for what I expected from a BiB that small; measurements say ca. 47 Hz @ -3 dB) and sounds very warm and natural as often described here. The locating of voices and instruments is fantastic with these coaxes and they have POWER without end! Even at higher levels no signs of distortions, just clear, crisp sound!
I have these speakers now for nearly one year and it seems that they still improved during that time. I have spent quite some time and money on these, but for me they are worth every bit of it. So I thought it was time to say thanks to all the contributors here on the forum, nice work!
Regards,
Martin
Time to say THANKS!!!
I haven't been building loudspeakers for 30 years (as a 20year old newb), but when moving to our new appartement I wanted to give it a try. The hearing room is somewhat special concerning it is a roof chamber with three different pitches of the roof, a door at the back wall hindering a symmetrical speaker placement and a pillar in the middle of the room. That's when I stumbled upon this MEGA-thread and was instantly infected with the idea that a speaker loading into the ceiling could be optimal for this kind of room. So I read through the whole (!) thread and that was quite an enlightenment: So many nice people, so many interesting ideas!!! My main problem: Corner placement was not possible because of other furniture that could not be placed elsewhere and for placement at least near a wall the maximal height of the speaker would be 120 cm (47.2") because of the droop going that far down => Not quite a BiB in the common sense! I didn't need a bass down to 30 Hz or so cause I have a dedicated Subwoofer, so I ran the BiB Calculator with some Full Range Speakers, but they didn't quite fit the bill. The speakers were all too tall and slim, mainly because of fs beeing too low for my special case. So I switched to musician/PA coax speakers and found some that came quite near, the best but also the most expensive (for my budget far too expensive) being the BMS 8CN552 (fs = 87.6 Hz, Qts = 0.29, Vas = 10.08 l / 0.356 ft3). That also correlated with my musical habits hearing mostly dub/electronic music at sometimes quite loud levels. What a lucky coincidence that a few weeks later I found (and was able to pick up) a quasi new pair of these exact speakers on ebay for half the price! So I did some further simulations with Martin J Kings spreadsheets and these are the (inner) dimensions I ended up with (because of cosmetical and practical considerations there are some small deviations to the results from the BiB calculator, but the simulations were rather promising):
Height: 117.8 cm / 46.4"
Width: 19.6 cm / 7.7"
Depth: 33.7 cm / 13.3"
Z driver: 45 cm / 17.7"
The housings are made of the best birch ply I could find here in Germany (not so easy and quite expensive) in 18 mm (0.7"). The internal divider is made of 19 mm (0.75") MDF. Because the depth of the speakers was to big for this enclosure I needed a supra baffle and they are the very fine work of a local wood turner (made of alder). Side note: I love frisbees and a frisbee was the model for th wood turner! As you can see in the photos I rasped out the back of the supra baffle to give the speakers more room to breathe as was suggested in this thread. As far as damping is concerned I lined up the front side of the internal divider and the front part of the side walls from the tip down to a bit below the speaker (sorry, can't remember what kind of material that was) and two layers of rock wool on the ground. I also made a frame with some speaker cloth for the top (mainly to not collect dust or childrens toys in the cabinets). The finish is three layers of slightly coloured (mainly to emphasize the contrast between alder and birch) oil wax and a final layer of a glossy clear oil wax. I'm very content with the look of the speakers!
Now to the most important, the sound: I use a miniDSP for the crossovers and the room correction. I made some measurements with REW and after the first iterations I didn't feel any need to further fiddle around with measurements and DSP settings, I just wanted to enjoy the sound. I have not much experience with high end speakers but these ones for me have it all! The bass even without the subwoofer goes quite deep (at least for what I expected from a BiB that small; measurements say ca. 47 Hz @ -3 dB) and sounds very warm and natural as often described here. The locating of voices and instruments is fantastic with these coaxes and they have POWER without end! Even at higher levels no signs of distortions, just clear, crisp sound!
I have these speakers now for nearly one year and it seems that they still improved during that time. I have spent quite some time and money on these, but for me they are worth every bit of it. So I thought it was time to say thanks to all the contributors here on the forum, nice work!
Regards,
Martin
Attachments
To be honest, there does not seem to be something like a top ten or absolute winner. I do think smaller Fostex drivers have been used most often, and Tangband. I did read the thread in one go, and initially people seemed to come here to get something Cain&Cain related on a DIY budget. So always Fostex. Over time, BIB has become more of a flexible design algorithm. People use whatever they have for a first build, or get something cheap and popular. Occasionally, someone has a Lowther, or a Voxativ, or some ultra-rare vintage thing and build.for that.
I am sort of OCD and prepare way too much, and have a hard time choosing between drivers, so I simulate a lot in Hornresp. You can get a a lot of drivers to work in a BIB, you just need to tweak it with love and enthusiasm.
Hi, I'm new to this BiB concept and I find it very solid. I thought I'd share what I am thinking with this group to see if I am onto something WRT the driver I am considering. I've searched this thread for Compound Horn and only got one cursory result back, so know this hasn't been discussed before in this mega thread. I would like to explore the idea of the Compound Horn using the BiB as the rear portion. The Driver I would use is the Audience A3, which can still be purchased from Meniscus Audio. I was initially inspired for this idea from:
DBH Loudspeakers Model 1 | 3D Warehouse
I envision a standard BiB in a narrow and tall format tuned down to ~ 35-45hz with some sort of small tractix horn sticking out the front. The key part is the higher sensitivity that can be had from this setup from the A3.
Wondering what this thread thinks about this?
Thanks.
DBH Loudspeakers Model 1 | 3D Warehouse
I envision a standard BiB in a narrow and tall format tuned down to ~ 35-45hz with some sort of small tractix horn sticking out the front. The key part is the higher sensitivity that can be had from this setup from the A3.
Wondering what this thread thinks about this?
Thanks.
Time to say THANKS!!!
Greets!
You're welcome! Thanks for sharing! Really sharp looking to boot!
GM
Greets!
You're welcome!
'Been there, done that', but predates the BIB thread, so the pipe horn design theory is a bit different and [re] defined HUGE [40+ ft^3 IIRC] due to loading a ~527 L Vas Altec 604E Duplex [co-ax] down to its ~25 Hz Fs. I use to have a link to it, though no clue at this late date the details or whether still on-line.
Regardless, with an effective upper mass corner [Fhm = 2*Fs/Qes'] of at least 270+Hz combined with a rising on axis response, a large conical WG like Unity/Synergy concept horns or better yet, a proper expanding curved flare to control its pattern above this point is the goal, but assume this will be too large/deep for you.
Still, using a truncated tractrix can work well enough if a foam mouth extension is incorporated to quell its reflections back to the throat.
In short, 'sounds' like a plan!
Note using Qes' for horn loading to ensure adequate net volume [Vb].
Qes' = Qes + any added series resistance: mh-audio.nl - Home
GM
Well, it looks like I was wrong about these still being available at meniscus. They show now as no longer available. Best bet is find some on ebay, or sweet talk the gods at Audience. For those who aren't familiar with the A3 it is basically built like a very small sub woofer, using xbl2 tech which gives huge x-max of 12mm, At the same time it is a very light mag-alu cone that is rigid, making for solid highs. It is known for it's exceptional mid range. I might not go with the compound horn, it would be a lot of experimenting with the compression chamber size, horn size, etc. I was just thinking that these drivers are not very sensitive at ~ 83spl. and the compound horn would give the most sensitivity.
I haven't had the time to play with the calculators yet, the thiele small of the A3 is:
Fs ~60hz(measured)
Vas 3 Liters
Qts 0.34(measured)
DCR 13 ohms
I will be powering these with some type of A biased Gain Clone. Probably around 25-35Watts. Seems these could be great drivers for bass.
I haven't had the time to play with the calculators yet, the thiele small of the A3 is:
Fs ~60hz(measured)
Vas 3 Liters
Qts 0.34(measured)
DCR 13 ohms
I will be powering these with some type of A biased Gain Clone. Probably around 25-35Watts. Seems these could be great drivers for bass.
Looks like a very tall narrow pipe 4in x 5.5in, if you want something from floor to ceiling using the A3. The low Vas is the reason. May not be what some want but in a small space might be the way to go. Maybe to improve midrange dispersion a small waveguide on the driver, would also help with/eliminate the need for baffle step.
After reading through the first part of this giant thread, it seems that there is some room for experimenting with size. I read that one of the drivers favored by some was the 4" Tangband Bamboo. It had a 3mm xmax. I might try a similar sized box, as suggested by Scottmoose, given that this little A3 has such a large xmax. So an outside 5w x 10d x 60h box with driver just above mid point? Hmm, sounds like a good starting point. I'm assuming I would need to put this in a corner to get everything out of it.
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Yes, the basic BIB algorithm assumes corner-loading and corner-placement.
I get pretty good correlation between my simulations in Hornresp and real-world response. This really helps to try out different lengths, volumes and driver placement. I recommend trying stuff out in Hornresp to get a feel for possibilities with a driver.
My workflow is that I make a pipe with s1=0.01 and S2=the mouth size, length whatever the calculated length is. Expansion P for parabolic. Then I make a second segment, s4=mouth size, length is 0.01 and expansion again P. Then select off-set driver OD. Then I can simply open the loudspeakerwizard, select automatic where it says manual in the horn parameters section, and then I can slide the driver anywhere along the length, Hornresp keeps the pipe the same shape etc. You can also change mouth size there, length, there's a section for pathlength difference, there's a section for stuffing, a section for driver arrangements, max-SPL and much more. I listed what I mostly use.
I also go to the filter section and mimic my known roomgain. Thr combination of BIB simulation and roomgain together gives a pretty reliable indication of response.
I get pretty good correlation between my simulations in Hornresp and real-world response. This really helps to try out different lengths, volumes and driver placement. I recommend trying stuff out in Hornresp to get a feel for possibilities with a driver.
My workflow is that I make a pipe with s1=0.01 and S2=the mouth size, length whatever the calculated length is. Expansion P for parabolic. Then I make a second segment, s4=mouth size, length is 0.01 and expansion again P. Then select off-set driver OD. Then I can simply open the loudspeakerwizard, select automatic where it says manual in the horn parameters section, and then I can slide the driver anywhere along the length, Hornresp keeps the pipe the same shape etc. You can also change mouth size there, length, there's a section for pathlength difference, there's a section for stuffing, a section for driver arrangements, max-SPL and much more. I listed what I mostly use.
I also go to the filter section and mimic my known roomgain. Thr combination of BIB simulation and roomgain together gives a pretty reliable indication of response.
Hmm, thanks Ivo. That is a nice primer on Hornresp, which has a bit of a learning curve. I'll try to do some sims on that at some point soon. After more reading Scottmoose was wrong, he feels, about the box size for the 4" TB driver. He suggested to chop it down to around 4' tall. I'm now thinking of going with a 4.5"w x 9"d x 50"h box, on stands to get them closer to the ceiling. With the A3 driver z then moved down a ways closer to the 0.4 than the ideal 0.2 z figure. This should be better for bass, which is what I expect to get from these A3 large xmax drivers.
Thank you for sharing. Behind the many pages of discussion, this thread really is about his legacy and generosity. It's moving to read feelings about the man himself.
I used to go to those RM fests. They are great. I've certainly heard of Cain & Cain, though I don't remember if I was in their room. It seems clear that Terry has given quite a gift to diy. He is missed.
Since I will be using a SS amp(Gainclone) and my A3 driver selection is a bit low in Qms, Qts I should probably use some series R? Maybe use that 30AWG magnet wire trick that Terry showed us? I'm still trying to figure out the importance of the various Qs in driver selection.
Since I will be using a SS amp(Gainclone) and my A3 driver selection is a bit low in Qms, Qts I should probably use some series R? Maybe use that 30AWG magnet wire trick that Terry showed us? I'm still trying to figure out the importance of the various Qs in driver selection.