Scott's Hemp BiB specs
Scott,
I'd been regretting asking this as I didn't want to detract much from the original topic, but I'm sure someone will run across this in a Google search and it might be beneficial. 🙂
I've been drawing up some more detailed plans before I make any wood cuts and have been questioning my calculations.
My drawings keep having an issue with the internal baffle running through the diameter of where the speaker should go. I figure either I'm reading the description wrong or my scaled drawing is just messed up.
"Driver 28.75in from internal sealed end." - I take this to mean the CENTER of the driver, straight down 28.75in, more or less from the top of the enclosure (where the baffle meets the corner). According to the measuring drawings on zillaspeak's How to build a BiB, I'd think the 28.75in is the "Z Driver" or "So".
"Baffle terminates 14.875in from base & internal left & right side walls." I'd assume this was the internal baffle that separates the enclosure to simulate the full line length. Is this correct? If so, according to the zillaspeak diagrams, I'd measure from the bottom of the cabinet, up to 14.875in, and also shows A = B = C = Depth / 2, which would be 8" depth / 2, which 14.875" is not 4". So I'm getting that part wrong, for sure. 🙂 I'd assume the lower end of the internal baffle is to be equidistant between the sides and bottom.
A final question, should I reverse the baffle's direction for the other enclosure, and then have each speaker in each enclosure preferably to the "inner" sides of the enclosure, as opposed to on the extreme left and right, being a further distance away? I assume this would depend on my listening distance as to how far apart each driver should be. I assume it'd be easier to have each speaker near the center of my listening area, if that makes sense.
I'm probably going to order the new "HempMatrix" versions of the FR8. I have to look still to see if the specs will not change my enclosure design, however. I've got myself a nice circular saw, a bunch of clamps, and a cleaned basement to construct everything. I'll probably start this weekend, hooray.
Scott,
I'd been regretting asking this as I didn't want to detract much from the original topic, but I'm sure someone will run across this in a Google search and it might be beneficial. 🙂
I've been drawing up some more detailed plans before I make any wood cuts and have been questioning my calculations.
My drawings keep having an issue with the internal baffle running through the diameter of where the speaker should go. I figure either I'm reading the description wrong or my scaled drawing is just messed up.
"Driver 28.75in from internal sealed end." - I take this to mean the CENTER of the driver, straight down 28.75in, more or less from the top of the enclosure (where the baffle meets the corner). According to the measuring drawings on zillaspeak's How to build a BiB, I'd think the 28.75in is the "Z Driver" or "So".
"Baffle terminates 14.875in from base & internal left & right side walls." I'd assume this was the internal baffle that separates the enclosure to simulate the full line length. Is this correct? If so, according to the zillaspeak diagrams, I'd measure from the bottom of the cabinet, up to 14.875in, and also shows A = B = C = Depth / 2, which would be 8" depth / 2, which 14.875" is not 4". So I'm getting that part wrong, for sure. 🙂 I'd assume the lower end of the internal baffle is to be equidistant between the sides and bottom.
A final question, should I reverse the baffle's direction for the other enclosure, and then have each speaker in each enclosure preferably to the "inner" sides of the enclosure, as opposed to on the extreme left and right, being a further distance away? I assume this would depend on my listening distance as to how far apart each driver should be. I assume it'd be easier to have each speaker near the center of my listening area, if that makes sense.
I'm probably going to order the new "HempMatrix" versions of the FR8. I have to look still to see if the specs will not change my enclosure design, however. I've got myself a nice circular saw, a bunch of clamps, and a cleaned basement to construct everything. I'll probably start this weekend, hooray.
mrpopgun said:
Greets!
This is a problem with some drivers, so folks add a supra baffle to get the desired clearance. Putting both drivers below the tweeter will change the response some, but it will vary depending on the room, etc., so don't have a clue whether it will make enough difference to matter. If you use TC's line length, then putting the top woofer in the driver position will in theory be a better solution.
GM
So, what if I were to really fold one of these things up, say 3 or 4 folds total instead of just the 1 we've been talking about all this time? Will the given line lengths, Zdriver positons and mouth areas still be appropriate? What new issues will this introduce and how might they be reduced?
Kensai
Kensai
Yeah, the Supra baffle idea hit me last night in sort of a 'duh' moment. Besides, thay would give me the opportunity to create two baffles - 1 with an MTM config and another with a TMM config then see what the difference is when swapping them out.
Looks like I need to go buy some plywood!
Thanks!
Looks like I need to go buy some plywood!
Thanks!
MrBubbs -re the driver positioning: this is why I said a while back somewhere on the thread that an external suprabaffle to space the driver out from the internal baffle will be needed so the magnet clears it. It's the frame of the FR8 that's the main issue as the magnet isn't too wide. Nobody believed me though. 
😉 (Actually more a case of my meaning was missed as it was part of a longer post).
The internal baffle will terminate 14.875in equidistant from the floor, and, in this cabinet's case, because it's flipped sideways, the right and left sidewalls.
Hope this helps
Scott
😉 (Actually more a case of my meaning was missed as it was part of a longer post). The internal baffle will terminate 14.875in equidistant from the floor, and, in this cabinet's case, because it's flipped sideways, the right and left sidewalls.
Hope this helps
Scott
planet10 said:
No magnetic attraction to the cone what-so-ever.
It could be a metal alloy thou -- still my 1st call would be a hi-tech plastic. I'd have to cut it to find out -- and i'm not ready to do that 🙂
dave
I guess we can assume TL is right....
goes a long way to illustrate that cone material can't be lumped into paper, metal, plastic, etc...
dave
goes a long way to illustrate that cone material can't be lumped into paper, metal, plastic, etc...
dave
No worries, Scott. 🙂
I haven't cut anything yet and I was just making sure my calculations were correct. I definitely remembered about the extra baffle to ensure the magnet clears. Thanks for the design too! A friend gave me an idea too.. the first song that will be played is.. you guessed it, the theme from 2001 🙂 Muhaha!
I haven't cut anything yet and I was just making sure my calculations were correct. I definitely remembered about the extra baffle to ensure the magnet clears. Thanks for the design too! A friend gave me an idea too.. the first song that will be played is.. you guessed it, the theme from 2001 🙂 Muhaha!
Scottmoose said:MrBubbs -re the driver positioning: this is why I said a while back somewhere on the thread that an external suprabaffle to space the driver out from the internal baffle will be needed so the magnet clears it. It's the frame of the FR8 that's the main issue as the magnet isn't too wide. Nobody believed me though.
The internal baffle will terminate 14.875in equidistant from the floor, and, in this cabinet's case, because it's flipped sideways, the right and left sidewalls.
Hope this helps
Scott
TL mentioned to me that he thought it was some ceramic material on the cone, like Aluminum oxide. That could lessen residual magnetivity to ~neglegible, no? I would guess this situation.
I think these might be great little drivers... are you planning on spooling them up soon Dave?
I think these might be great little drivers... are you planning on spooling them up soon Dave?
dmason said:
I'm hoping they are pretty good. An aweful lot of stuff in the queue, not sure when we'll get to them.
dave
I just want to make sure I understand Line Length.
From what I read here and on zillaspeak, it looks like line length is calculated from inside top of baffle, to bottom center and back up the speaker to the center of the mouth. Is that correct or does it more closely hug the internal baffle?
From what I read here and on zillaspeak, it looks like line length is calculated from inside top of baffle, to bottom center and back up the speaker to the center of the mouth. Is that correct or does it more closely hug the internal baffle?
Theoretically, it's measured as being equidistant from the panels. However, there's a danger of getting too worried about this. The room has a far greater impact upon the response than minor changes in line length. 95% of the time, length / 2 works fine. It's only really when you start getting to very large (deep) cabinets that you get potentially significant differences creeping in.
That's good. Does ceiling height factor in for loading? If a line length of 120" is called for but my ceilings are 9'-10' tall instead of the standard 8', do I need to vary things a bit to optomize?
Thanks
Thanks
Scottmoose said:
I had the opposite concern when I was going to build the Hemp BIBs,
worried it would be too close to the ceiling. But that and the problems
with delivery of the hemp drivers has forced a rethink.
Now looking to build a 168 BIB.
Scott, a few pages back Leglandu asked about the difference between the
line lengths of the 168 and 166, wondering whether the 168 could be
made longer. You said, "This was one of my earlier cabs, and since then
I've revised some of my views".
Taking a fresh look at it, are there any changes that you could make to
improve it?
Thanks, John
worried it would be too close to the ceiling. But that and the problems
with delivery of the hemp drivers has forced a rethink.
Now looking to build a 168 BIB.
Scott, a few pages back Leglandu asked about the difference between the
line lengths of the 168 and 166, wondering whether the 168 could be
made longer. You said, "This was one of my earlier cabs, and since then
I've revised some of my views".
Taking a fresh look at it, are there any changes that you could make to
improve it?
Thanks, John
Once i did found these on a page her
::::::::::::::::::::::::::::::::::::::::::::::::::::
Hello all,
I just stumbled on this thread today (and this site). I have used the old 168S for many previous projects and ended up with a couple of AER MK1 drivers a few years ago as well.
The best I have managed to get to so far is an OB design with the AER's, adding two Seas CA25FEY drivers (separate amp and active filter) in the baffle to help with bass. Being an engineer though, I am a varm believer in keeping things simple, so to do away with the bass drivers and use the AER's for everything has been my goal from the begining, but I have never succeded.
Based on all the comments so far, this seems to be a possible solution, extend the response without giving up the fantastic mid/high from the OB design.
I have looked for a simulation / optimization SW to see what dimensions I would need and what response I could expect, is this available? The AER MK 1 parameters are:
Frequency response +/- 2.5dB 20 Hz - 21 kHz
Voice coil impedance (nominal) 16 ohm
Nominal impedance 16 ohm
Nominal Power Handling 100W
Air gap width 1 mm
Flux density 1.9 Tesla
Diaphragm Twin-paper
Nominal air resonance 38.1 Hz
Sensitivity at 1m/1kHz/1Watt 102.5 db
Maximum voice coil travel �} 1 mm
Total Q Factor 0.40
Electrical Q Factor 0.42
Mechanical Q Factor 6.22
Equivalent Volume Suspension 74 litre
Bl 9.5 N/A
L(vc) 1.55mH
Greatfull for any help or pointer in the right direction.
Thanks / Peter
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
So me a musician and woodworking for 3 decads
maybe an overkill but who cares
going wild aand crayz
I do have acces to Douglas Pine maybe not ok my typo
could be cut to stripes could be glued togeteher each second inverted maybe two plies. My ceiling 20.9 feet. Would be cheaper as anz so called high end sealed speaker. I do know AER in Germanz very well, a friend of mine. Conected by dadoes and glued with marine epoxzy the speaker in a bowl like the original BIB's external corners rounded. The wood would be oiled.
a beaty, but as a musician how to calculated this beast, anzzsuggestions??
Any ideas welcome
Régine Marie
it is very serious, crazy but nice anyway
and another silly question
tube or Zenlike single MOS....
Guys I do need your ideas
🙂 🙂
::::::::::::::::::::::::::::::::::::::::::::::::::::
Hello all,
I just stumbled on this thread today (and this site). I have used the old 168S for many previous projects and ended up with a couple of AER MK1 drivers a few years ago as well.
The best I have managed to get to so far is an OB design with the AER's, adding two Seas CA25FEY drivers (separate amp and active filter) in the baffle to help with bass. Being an engineer though, I am a varm believer in keeping things simple, so to do away with the bass drivers and use the AER's for everything has been my goal from the begining, but I have never succeded.
Based on all the comments so far, this seems to be a possible solution, extend the response without giving up the fantastic mid/high from the OB design.
I have looked for a simulation / optimization SW to see what dimensions I would need and what response I could expect, is this available? The AER MK 1 parameters are:
Frequency response +/- 2.5dB 20 Hz - 21 kHz
Voice coil impedance (nominal) 16 ohm
Nominal impedance 16 ohm
Nominal Power Handling 100W
Air gap width 1 mm
Flux density 1.9 Tesla
Diaphragm Twin-paper
Nominal air resonance 38.1 Hz
Sensitivity at 1m/1kHz/1Watt 102.5 db
Maximum voice coil travel �} 1 mm
Total Q Factor 0.40
Electrical Q Factor 0.42
Mechanical Q Factor 6.22
Equivalent Volume Suspension 74 litre
Bl 9.5 N/A
L(vc) 1.55mH
Greatfull for any help or pointer in the right direction.
Thanks / Peter
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
So me a musician and woodworking for 3 decads
maybe an overkill but who cares
going wild aand crayz
I do have acces to Douglas Pine maybe not ok my typo
could be cut to stripes could be glued togeteher each second inverted maybe two plies. My ceiling 20.9 feet. Would be cheaper as anz so called high end sealed speaker. I do know AER in Germanz very well, a friend of mine. Conected by dadoes and glued with marine epoxzy the speaker in a bowl like the original BIB's external corners rounded. The wood would be oiled.
a beaty, but as a musician how to calculated this beast, anzzsuggestions??
Any ideas welcome
Régine Marie
it is very serious, crazy but nice anyway
and another silly question
tube or Zenlike single MOS....
Guys I do need your ideas
🙂 🙂
floor loaded BIB
and if the AER will not work
what about a floor loaded 8 Hemp BiB
I do have a wooden pine floor
a subwoofer needed ??
the C&C are the best looking I've ever seen
but the sub who knows something about. ??
I do know a lot's of questions but horns are for me
the only way to go to have an idea of live sound
and if the AER will not work
what about a floor loaded 8 Hemp BiB
I do have a wooden pine floor
a subwoofer needed ??
the C&C are the best looking I've ever seen
but the sub who knows something about. ??
I do know a lot's of questions but horns are for me
the only way to go to have an idea of live sound
In my limited opinion the AER looks really, really good for a BIB. Qts/40, Fs/38, Vas/74L, and the bonus 104db rating. 
Laissez les bon temps rouller
Laissez les bon temps rouller
Oh boy. Lot of things to wade through.
OK, first up, FWIW, I'd shift the original non 'E' Sigma line length to 128in, with a zdriver at 27in. The 168ESigma can be pushed a little harder -a 140in line length with a zdriver of 30.25in would be nice.
The AER? Nice driver. I was listening to a pair yesterday, run OB with a Supravox bass driver (Jame's D's Quasar). Outstanding. A BIB for them will have to be pretty large owing to the migh Q and Vas (in BIB terms, mid Q is fine if Vas is low; flip side is that you can get away with a relatively high Vas if Q is low. YMMV).
Line length 160in. Zdriver 34in. Sl=250in^3.
Optimise for ceiling height? That'd need someone with more math ability that I have. Martin or Greg could do it I'm sure, but not me. Generally, they're pretty forgiving and work passably with just a rear wall to load them. In a corner, even if the ceiling is too high, you've got two reflection boundary conditions, so it should be happy enough.
OK, first up, FWIW, I'd shift the original non 'E' Sigma line length to 128in, with a zdriver at 27in. The 168ESigma can be pushed a little harder -a 140in line length with a zdriver of 30.25in would be nice.
The AER? Nice driver. I was listening to a pair yesterday, run OB with a Supravox bass driver (Jame's D's Quasar). Outstanding. A BIB for them will have to be pretty large owing to the migh Q and Vas (in BIB terms, mid Q is fine if Vas is low; flip side is that you can get away with a relatively high Vas if Q is low. YMMV).
Line length 160in. Zdriver 34in. Sl=250in^3.
Optimise for ceiling height? That'd need someone with more math ability that I have. Martin or Greg could do it I'm sure, but not me. Generally, they're pretty forgiving and work passably with just a rear wall to load them. In a corner, even if the ceiling is too high, you've got two reflection boundary conditions, so it should be happy enough.
