Be careful using the BLH worksheets to model the BIB design. The BLH worksheets assume a significant mouth size that is bordered by the floor which effectively doubles the area and also the acoustic impedance boundary condition. That is why the curves look smoother as frequency increases. If your BIB design is up against the rear wall then the BLH worksheet is probably more accurate. If you BIB design is in the corner then additional smoothing will occur.
I am now actively working on extending the horn theory articles and upgrading to the horn worksheets. So a corner loading calculation is a possibility for later this winter along with a few other advances.
I am now actively working on extending the horn theory articles and upgrading to the horn worksheets. So a corner loading calculation is a possibility for later this winter along with a few other advances.
FE164
Hi Scottmoose,
I'm relatively new on this forum (used to hang around the Fullrangeforum), so I have to post here (can't yet send emails).
I've been eyeing the BIBs for months now, I was almost set to build the FE166e BIB, but came across a nice pair of Coral Beta 6 and... well, I still want to build the BIBs, but the Corals are so sweet.
I have very limited specs for the coral drivers. here they are:
Radius 6,5 inches
Eff. 93db
Fs 50Hz
Qo: 0,34
I do not have the VAS
My guess would be that they resemble more the FE164, with higher QTS and lower VAS... maybe?
I just don't know if the FE166 suggested BIB would do the trick. I guess an educated opinion would be greatly appreciated as I have a limited supply of solid Oak panels that I want to use for this. I'd much prefer get it right the first time.
Thanks.
Hi Scottmoose,
I'm relatively new on this forum (used to hang around the Fullrangeforum), so I have to post here (can't yet send emails).
I've been eyeing the BIBs for months now, I was almost set to build the FE166e BIB, but came across a nice pair of Coral Beta 6 and... well, I still want to build the BIBs, but the Corals are so sweet.
I have very limited specs for the coral drivers. here they are:
Radius 6,5 inches
Eff. 93db
Fs 50Hz
Qo: 0,34
I do not have the VAS
My guess would be that they resemble more the FE164, with higher QTS and lower VAS... maybe?
I just don't know if the FE166 suggested BIB would do the trick. I guess an educated opinion would be greatly appreciated as I have a limited supply of solid Oak panels that I want to use for this. I'd much prefer get it right the first time.
Thanks.
Cheers for that, Jeff.
Martin -good news re the potential corner loading! I suspected as much from your last email. I figured the BLH sheet would be useful in this respect (as well as the ability to accurately plot WxD dimensions at specific points in the line) as the cabinets are intended for rear-wall / corner placement -it makes quite a significant difference. A little less so in shifting flare profiles, which surprised me -any thoughts?
gychang -yes, that driver position's fine.
Daze. Good question. Can't say I blame your for grabbing the Beta 6s. Problem is, of course, that to the best of my knowledge, there are no measured T/S parameters anywhere on the 'net. I've got some very limited ones for the Flat 6, which I gather are roughly similar to the Beta, so I used those, with Martin's Parameter check sheet to come up with a BL factor, and some educated guesswork. Fs is higher than the Fostex drivers, if the Flat6 is anything to go by, so it won't go quite as low. Still not bad though -you'll get a good 40Hz out of it, providing it's in a corner -this one will likely need the extra boundary to get the LF up into line.
Line 120in
Zdriver 24in
Sl=80.625in^2
Hope this is of some use
Scott
Martin -good news re the potential corner loading! I suspected as much from your last email. I figured the BLH sheet would be useful in this respect (as well as the ability to accurately plot WxD dimensions at specific points in the line) as the cabinets are intended for rear-wall / corner placement -it makes quite a significant difference. A little less so in shifting flare profiles, which surprised me -any thoughts?
gychang -yes, that driver position's fine.
Daze. Good question. Can't say I blame your for grabbing the Beta 6s. Problem is, of course, that to the best of my knowledge, there are no measured T/S parameters anywhere on the 'net. I've got some very limited ones for the Flat 6, which I gather are roughly similar to the Beta, so I used those, with Martin's Parameter check sheet to come up with a BL factor, and some educated guesswork. Fs is higher than the Fostex drivers, if the Flat6 is anything to go by, so it won't go quite as low. Still not bad though -you'll get a good 40Hz out of it, providing it's in a corner -this one will likely need the extra boundary to get the LF up into line.
Line 120in
Zdriver 24in
Sl=80.625in^2
Hope this is of some use
Scott
Attachments
Hey Scott,
Would the lengthening of the line length by say 24 or more inches make a difference to the depth of bass or is it more to do with length and width etc. Most likely a combination of both.... Changed my mind about the driver too '' to the fostex fw167 mainly because the Sm doesn't have to be quite so big and it is shielded. I'm aiming for 30Hz clean pretty bass. I can quite easily make BIB's about 80 to 90 inches tall and still have 3 ft till the ceiling!
I figured the UBBIB (under-bed-bass-BIB) is gonna take some (alot) of experimentation to get right. Oh and a bit more experience.... I WILL SUCCEED though...even if physics says no it won't...'
'
Stroop
Would the lengthening of the line length by say 24 or more inches make a difference to the depth of bass or is it more to do with length and width etc. Most likely a combination of both.... Changed my mind about the driver too '
' to the fostex fw167 mainly because the Sm doesn't have to be quite so big and it is shielded. I'm aiming for 30Hz clean pretty bass. I can quite easily make BIB's about 80 to 90 inches tall and still have 3 ft till the ceiling!I figured the UBBIB (under-bed-bass-BIB) is gonna take some (alot) of experimentation to get right. Oh and a bit more experience.... I WILL SUCCEED though...even if physics says no it won't...'
'Stroop
Hi guys,
Slow night at work (post floods and earthquake). So I tried to read this entire thread. Ouch! Gave up at page 38 and jumped up here.
This is all very ineresting because of my involement in the BBBIB thread. That's Punkrokr's BIB with the Emminence Beta 12 LTA.
There seems to be lots of sims going on, but how about building. Was there ever a BIB built using the Hemp 8? Or the little TB 4" Bamboo? How about the Monocor 5"?
Godzilla has a lot of Scottmoose and GM sims on his site, but what about finished speakers? Is there a list somewhere of what has been built? (Sure wish the forum would let you search within a single thread.)
I do see a few finished BIBs on Godzilla's site. Are there others?
Slow night at work (post floods and earthquake). So I tried to read this entire thread. Ouch! Gave up at page 38 and jumped up here.
This is all very ineresting because of my involement in the BBBIB thread. That's Punkrokr's BIB with the Emminence Beta 12 LTA.
There seems to be lots of sims going on, but how about building. Was there ever a BIB built using the Hemp 8? Or the little TB 4" Bamboo? How about the Monocor 5"?
Godzilla has a lot of Scottmoose and GM sims on his site, but what about finished speakers? Is there a list somewhere of what has been built? (Sure wish the forum would let you search within a single thread.)
I do see a few finished BIBs on Godzilla's site. Are there others?
Stroop -as you've got the space, then yes; you can make the line longer. I restrict them to about 140in, even with lowish Fs drivers, as that's about the maximum most Significant Other's can stomach. If that's not an issue...
Take line length to 170in, which will mean a cabinet ~85in tall.
Zdriver 34in
Sl=75in^2.
Stuff the entire first half of the line with 0.25lbs ft^3 of hollow-fibre damping material. That'll get you down to 30Hz at the very least.
Pano -yes, there are quite a few other BIBs out there. I own two for example, both of which are out on loan at the moment; one has Monacor SPH-60X, the other FF165K. A friend of mine owns a pair with FF225K that I built for him. Blumenco has built a pair for his FE166ES-Rs, and currently runs FE167E in them. Dan Mason has FE168ESigmas in his, and is currently building another pair for the FF165K drivers, but with non-driver specific dimensions which will allow him to roll different drivers to decent effect with all of them.
Recently, there's been a pair built for the FE108ESigma to excellent results, another for the FE103E, and there are quite a few in construction at present to the best of my knowledge. Jeff (Godzilla) for example, has two pairs in the works, one for his non 'E' model FE168Sigma drivers, the other for a pair of TB Bamboo units. Thing is, Jeff's time is limited, and we don't want to be taking up too much of his bandwidth / site space with the BIB pages that he could dedicate to his other speaker projects & interests, to say nothing of his business!
Best
Scott
Take line length to 170in, which will mean a cabinet ~85in tall.
Zdriver 34in
Sl=75in^2.
Stuff the entire first half of the line with 0.25lbs ft^3 of hollow-fibre damping material. That'll get you down to 30Hz at the very least.
Pano -yes, there are quite a few other BIBs out there. I own two for example, both of which are out on loan at the moment; one has Monacor SPH-60X, the other FF165K. A friend of mine owns a pair with FF225K that I built for him. Blumenco has built a pair for his FE166ES-Rs, and currently runs FE167E in them. Dan Mason has FE168ESigmas in his, and is currently building another pair for the FF165K drivers, but with non-driver specific dimensions which will allow him to roll different drivers to decent effect with all of them.
Recently, there's been a pair built for the FE108ESigma to excellent results, another for the FE103E, and there are quite a few in construction at present to the best of my knowledge. Jeff (Godzilla) for example, has two pairs in the works, one for his non 'E' model FE168Sigma drivers, the other for a pair of TB Bamboo units. Thing is, Jeff's time is limited, and we don't want to be taking up too much of his bandwidth / site space with the BIB pages that he could dedicate to his other speaker projects & interests, to say nothing of his business!
Best
Scott
Another note of caution, or maybe just a point worth making, the CSA of a line can be expressed as a ratio of Sd, as W x D, or just entered as a numerical value with units of length squared. None of the worksheets care how you enter these properties as long as MathCad can calculate an area with correct units, the actual units do not matter either even in an individual calculation. So if the worksheet has default areas expressed as ratios of Sd it can be changed to W x D, this can be for a single entry or all entries. You can mix and match methods of defining CSA, in the end MathCad calculates an area in m^2 and that is what is stored. Also, the specific W x D aspect ratio does not play into the calculations at this time.
Thanks for that Martin -useful to know.
pano. -no, unfortunately not. I've got most of his albums, but Caverna Magica, and Down to the Moon were the ones I never was able to get hold of. Bet it'd sound good on BIBs though. Re the driver, I'd go with one of the 6 1/2in series; either the FE166/7E, the FF165K or the FE168ESigma. Sigma is the best driver, but isn't exactly cheap. Most people would play safe and use the 166 or 167. The 165 is smoother, and has more bass at the expense of some HF extension, and works better in smaller rooms.
pano. -no, unfortunately not. I've got most of his albums, but Caverna Magica, and Down to the Moon were the ones I never was able to get hold of. Bet it'd sound good on BIBs though.
Re the driver, I'd go with one of the 6 1/2in series; either the FE166/7E, the FF165K or the FE168ESigma. Sigma is the best driver, but isn't exactly cheap. Most people would play safe and use the 166 or 167. The 165 is smoother, and has more bass at the expense of some HF extension, and works better in smaller rooms.Scottmoose said:
Thanks for the info,
What I have gathered is that the Flat6 is quite different. The Flat6 specs give:
Fs: 45 Hz
Eff. 92 dB
Flux: 54700 Maxwell
Effective cone Radius: 6,45 in.
Mo: 6,7 gr.
Fo: 0,42
The Beta6 specs give:
Fs: 50 Hz
Eff. 93 dB
Flux: 83000 Maxwell
Effective cone Radius: 6,7 in.
Mo: 6,7 gr.
Fo: 0,36
I'm not sure this would make the greatest difference. But it is all I got. Please let me know what you think.
Many thanks, I appreciate your input.
Daze
You're welcome.
I doubt the differences shown in the above would be likey to make a huge difference. Without the major T/S parameters we're just guessing anyway. Unfortunately, none of the above are really useful parameters in this case (aside from Fs). Greg or Martin might be able to do something with them though.
The Flat6 Fs you mention differs markedly from another I've seen which was measured as 68Hz. I'd err on the side of caution and base the length at least around that, rather than risk ending up with a huge hole in the mid-bass (which is what happens if you go too far below Fs). However, you can increase the depth of the cabinetif you wish -better to be too big as you can always damp it down than too small, and not have enough volume.
Greg, any thoughts?
I doubt the differences shown in the above would be likey to make a huge difference. Without the major T/S parameters we're just guessing anyway. Unfortunately, none of the above are really useful parameters in this case (aside from Fs). Greg or Martin might be able to do something with them though.
The Flat6 Fs you mention differs markedly from another I've seen which was measured as 68Hz. I'd err on the side of caution and base the length at least around that, rather than risk ending up with a huge hole in the mid-bass (which is what happens if you go too far below Fs). However, you can increase the depth of the cabinetif you wish -better to be too big as you can always damp it down than too small, and not have enough volume.
Greg, any thoughts?
Re hemp 8 BIB
I built the 200 sq inch BIB for the hemp 8 and love that driver.I have used many fostex in various horns 108 ez 126e, 206e etc much prefer the hemp particularly for the mid range--beautiful tone. BIB bass is wonderful having some qualities like open baffle. If you can stand the size I heartily recommend the Hemp 8 BIB. Jim G.
I built the 200 sq inch BIB for the hemp 8 and love that driver.I have used many fostex in various horns 108 ez 126e, 206e etc much prefer the hemp particularly for the mid range--beautiful tone. BIB bass is wonderful having some qualities like open baffle. If you can stand the size I heartily recommend the Hemp 8 BIB. Jim G.
Jim G.
I see in your description of your Hemp BIB's (a few pages back) that you built them out of "regular ply". Have you had any resonance/buzzing prolems with the cheaper stuff? What sort of damping/hf absorbtion materials did you use, and how much hf/mid range leaks out of the mouth?
I'm just curious. I really need to get of my a$$ and build a pair of BIB cabinets.
Paul
I see in your description of your Hemp BIB's (a few pages back) that you built them out of "regular ply". Have you had any resonance/buzzing prolems with the cheaper stuff? What sort of damping/hf absorbtion materials did you use, and how much hf/mid range leaks out of the mouth?
I'm just curious. I really need to get of my a$$ and build a pair of BIB cabinets.
Paul
Scottmoose said:
The graphs are a bit misleading as well since the last 2 are plotted on a different vertical scale... here is a composite (red/green/purple in the order Scott posted).
Note that Godzilla's overlay is invalid because he did not adjust the vertical scale for the red curve to the other curves (ie he has 50 dB of amplitude data plotted in 60 dB of vertical space -- maybe more since that one dip goes below the x axis)
dave
Attachments
Scottmoose said:
I believe that can be adjusted. I mailed Martin about the plots and althou i don't think he completely understood what i was asking he did send some useful info that i have been remiss in sending you. (ie you can turn the blue line off -- i was more interested in having it plot behind the red curve)
Another thing that would be nice is to have greater vertical height in the graphs... in the existing format, peaking at the bottom is somewhat visually minimized by the compact vertical scale (this i just learned when scaling the Dicks' BR curves to compare to the ML-TL curve you sent me).
dave