Theoretically the difference will be relatively small. That said, Terry Cain's baffles do look good, and I believe there's a theory around that they help scatter reflections off the driver surround.
GM does it again!
You think there's not much left to experiment with, and not only does he disprove it, he goes and makes another great suggestion that opens up a multitude of new pathways! Hand on heart, we all owe you, big time, for your advice and contributions, here and elsewhere.
Oddly enough, I've been planning on taking a closer look at Karlson's, albeit in an area unrelated to the BIB, at some point soon, as they've interested me for a while, but I've never really got around to doing anything about it. Didn't you come up with an Excel spreadsheet a while back for these Greg? I think I've got a copy somewhere on one of my HDDs, but my math ability ran out before I could before I could really understand it -probably needed a context, so I'll study these original articles on the site you linked to with great interest.
Assuming I'm reading you right, you're suggesting that the top would be left open, while the slot is sliced in the rear baffle, wide at the top, tapering downward, as a superior alternative to slicing said open top at, say, a 45 (or whatever) degree angle?
I've just got my 165 enclosures back (they were on loan for a couple of weeks), so I'm going to try this one out like a shot. Something ~12in long is flitering through the brain at the moment, as for my box that ratio would result in something very similar to the K-15, but don't hold me to that! BTW -would this have any effect regarding line-length?
All the best
Scott
GM does it again!
You think there's not much left to experiment with, and not only does he disprove it, he goes and makes another great suggestion that opens up a multitude of new pathways! Hand on heart, we all owe you, big time, for your advice and contributions, here and elsewhere. Oddly enough, I've been planning on taking a closer look at Karlson's, albeit in an area unrelated to the BIB, at some point soon, as they've interested me for a while, but I've never really got around to doing anything about it. Didn't you come up with an Excel spreadsheet a while back for these Greg? I think I've got a copy somewhere on one of my HDDs, but my math ability ran out before I could before I could really understand it -probably needed a context, so I'll study these original articles on the site you linked to with great interest.
Assuming I'm reading you right, you're suggesting that the top would be left open, while the slot is sliced in the rear baffle, wide at the top, tapering downward, as a superior alternative to slicing said open top at, say, a 45 (or whatever) degree angle?
I've just got my 165 enclosures back (they were on loan for a couple of weeks), so I'm going to try this one out like a shot. Something ~12in long is flitering through the brain at the moment, as for my box that ratio would result in something very similar to the K-15, but don't hold me to that! BTW -would this have any effect regarding line-length?
All the best
Scott
Scottmoose said:
You're right and I appologize for keeping you all distracted...
But nevertheless, thank you all for all the information!!
I'll post pictures as soon a I get building...
BTW, very nice idea to further investigate Karlson transducers!
I grew up with Karlson cab's, wich my dad build when he was in his twenty's. He used the same 12" philips drivers as Herb did in his Voigt's (AD12002 as I recall, 8ohm version), driven by the sweetest Dual tube amp.
See where my interest comes from ?
Still got those cab's; drivers blown, particle board desintegrating, all dent and chamfered, but I just can't get to throwing them away...
I suppose it will be a new thread when you get to it, but I'm gonna subscribe to it
Thanks again and keep up the good work!
Empee
Nothing to apologise about -the BIB was your original query. A new thread might be a good idea though, as it'd be an interesting build anyway, whether it works or not! Thanks for the driver designation number for the 12in jobs BTW -I was wondering what it was.
Incidentally, as you clearly have a soft spot for K-Slots, you could perhaps try a variation of this pipe with a K-Slot rather than the regular vent when you get around to building the things. Looking at GM's (?) aforementioned spreadsheet and assuming that a) I'm reading it right, and b) you use an internal width of 250mm, with a line tuning of approximately 50Hz, then the sheet says you need a slot 380mm tall. Just a thought.
Best
Scott
Oh yes -did you like the picture of Herb's 8ft monsters? Like 'em or no, you can't deny they look impressive! I have to admit it, just looking at them, I want them to work. I have my doubts, but you never know.
Incidentally, as you clearly have a soft spot for K-Slots, you could perhaps try a variation of this pipe with a K-Slot rather than the regular vent when you get around to building the things. Looking at GM's (?) aforementioned spreadsheet and assuming that a) I'm reading it right, and b) you use an internal width of 250mm, with a line tuning of approximately 50Hz, then the sheet says you need a slot 380mm tall. Just a thought.
Best
Scott
Oh yes -did you like the picture of Herb's 8ft monsters? Like 'em or no, you can't deny they look impressive! I have to admit it, just looking at them, I want them to work. I have my doubts, but you never know.
Yihaa!!
That's what I needed!
I was allready thinking of a way to make the vent look more...
err..... "technical" ??
Was thinking about making a scoop-like bent in plywood or something, putting a funnel in front, maybe even a small horn just for the looks, but a K-slot is much more attractive!!
Oops,
Did I just imply that looks are more important than sound??
but as I'd like them to work,
I'm gonna do my utmost to correct any unefficiency's by stuffing and maybe the K-slot is an extra help getting it correct
Worth a try, as I can always cover it and make it square again...
I'll keep y'all posted
<< edit: >>
huh ?
seen this??
http://www.geocities.com/tadgesualdo/CornerFldVpExpslot.html
and/or
http://www.geocities.com/tadgesualdo/SpeakerPlans1.html
That's what I needed!
I was allready thinking of a way to make the vent look more...
err..... "technical" ??
Was thinking about making a scoop-like bent in plywood or something, putting a funnel in front, maybe even a small horn just for the looks, but a K-slot is much more attractive!!
Oops,
Did I just imply that looks are more important than sound??
but as I'd like them to work,
I'm gonna do my utmost to correct any unefficiency's by stuffing and maybe the K-slot is an extra help getting it correct
Worth a try, as I can always cover it and make it square again...
I'll keep y'all posted
<< edit: >>
huh ?
seen this??
http://www.geocities.com/tadgesualdo/CornerFldVpExpslot.html
and/or
http://www.geocities.com/tadgesualdo/SpeakerPlans1.html
Hey Scott, if you have the time what would a bass cab (floor loaded to the rear) look like with this driver? I would like to use a tweeter above it for a tall thin two-way. Any foreseeable problems with this set-up?
TANG BAND W4-992S 4" SHIELDED SUBWOOFER
Frequency range: 55-2,500 Hz
Fs: 55 Hz
SPL: 86 dB 1W/1m
Vas: .20 cu.ft.
Qms: 2.93
Qes: .40
Qts: .35
TANG BAND W4-992S 4" SHIELDED SUBWOOFER
Frequency range: 55-2,500 Hz
Fs: 55 Hz
SPL: 86 dB 1W/1m
Vas: .20 cu.ft.
Qms: 2.93
Qes: .40
Qts: .35
From many of the subjective posts on this thread about the unique sound the BIB throws (specifically it’s 3D bass) it might make sense to try ‘BIB Bass Horns’ along with ‘Open Baffle’ designs for an amazing holographic effect.
Just a thought.
http://www.zillaspeak.com/BibBassHorns.asp
Meanwhile, I finally got around to working on my latest Fostex 127e speaker (non BIB… small, thin, slotted design to be placed very close to a wall) which brings me closer to completing my 168S based BIB – which is just so BIG it’s difficult to work with. Only SIX more holes to cut!!! My front baffle’s three ply thick to clear the inside baffle. The cabinet will be heavy (tripled up on front and doubled up on back)… not including the base and drivers these things are already so heavy. In my mind I imagine them flanking my office book case… once positioned I hope they sound GREAT!
Then onto smaller TB Bamboo based BIBs for the kiddies playroom.
Peace,
Godzilla
Just a thought.
http://www.zillaspeak.com/BibBassHorns.asp
Meanwhile, I finally got around to working on my latest Fostex 127e speaker (non BIB… small, thin, slotted design to be placed very close to a wall) which brings me closer to completing my 168S based BIB – which is just so BIG it’s difficult to work with. Only SIX more holes to cut!!! My front baffle’s three ply thick to clear the inside baffle. The cabinet will be heavy (tripled up on front and doubled up on back)… not including the base and drivers these things are already so heavy. In my mind I imagine them flanking my office book case… once positioned I hope they sound GREAT!
Then onto smaller TB Bamboo based BIBs for the kiddies playroom.
Peace,
Godzilla
Godzilla, have a look at my post #840 in this thread. I have often raised the idea of running the full range speakers in OB with some form of subs. I had enquired about ELF subs but not everyone thought of it as a good idea ie., ELF sub, FR like 168EZ in OB with a ribbon super tweeter like Fountek JP3.
There are two issues to consider using a BIB sub and OB mid/high or full range combination:
1) Someone in this thread had made a direct comparison between OB and BIB and opined that the mids sounded "better" in a BIB. Will OB cause the mids to sound more analytical and less warm?
2) Won't the phase response of the system suffer as compared to FR BIB?
It is due to the above reasons, that I guess that ELF type sub, with an FR/ 2 way BIB physically placed above the sub cabinet will show forth the best of all desired characteristics.
There are two issues to consider using a BIB sub and OB mid/high or full range combination:
1) Someone in this thread had made a direct comparison between OB and BIB and opined that the mids sounded "better" in a BIB. Will OB cause the mids to sound more analytical and less warm?
2) Won't the phase response of the system suffer as compared to FR BIB?
It is due to the above reasons, that I guess that ELF type sub, with an FR/ 2 way BIB physically placed above the sub cabinet will show forth the best of all desired characteristics.
Hi Scott,
Two questions:
First: You mentioned about round super baffle (à la TC) few posts ago, do you know any rule about size and shape considering speaker baffle width and driver diameter?
Second: I have some OSB plywood left and I wanted to make a proto cab for breaking the two couples of drivers. Do you think OSB could be good used as internal layer (except for the internal baffle), overlayed with another 3/4" plywood or hard wood finish? (OSB seems rigid and unresonant...works well for my parquet...)http://www.howelumber.com/lumber.plywood.osb.htm
Thanks.
Ciao.Fab.
Moderators Note: portions of this post and the next one have been transferred to a split-off thread on supraBaffles http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636
Two questions:
First: You mentioned about round super baffle (à la TC) few posts ago, do you know any rule about size and shape considering speaker baffle width and driver diameter?
Second: I have some OSB plywood left and I wanted to make a proto cab for breaking the two couples of drivers. Do you think OSB could be good used as internal layer (except for the internal baffle), overlayed with another 3/4" plywood or hard wood finish? (OSB seems rigid and unresonant...works well for my parquet...)http://www.howelumber.com/lumber.plywood.osb.htm
Thanks.
Ciao.Fab.
Moderators Note: portions of this post and the next one have been transferred to a split-off thread on supraBaffles http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636
I think TC's baffles were originally sized as having a diameter approximately 7in over the driver. Not sure about them now, not having measured one. I doubt it'd be worth getting too worked up over the exact radii applied, so long as it smoothly curves down. There's math in there somewhere, but whatever it is is beyond my limited ablity at this stage.
Looking at that board, I don't see why not. Looks pretty good to me, and it almost certainly would be superior to MDF. Remember GM's advice though regarding the advantages of some lossy panels (the rear and a side panel I believe) which will be well worth exploring. I intend to do just that with the next pair of boxes I make. As a bonus, the material he advises for that -low density fibreboard (i.e. chipboard) is extremely cheap, which is always nice.
Looking at that board, I don't see why not. Looks pretty good to me, and it almost certainly would be superior to MDF. Remember GM's advice though regarding the advantages of some lossy panels (the rear and a side panel I believe) which will be well worth exploring. I intend to do just that with the next pair of boxes I make. As a bonus, the material he advises for that -low density fibreboard (i.e. chipboard) is extremely cheap, which is always nice.
Hi Scott
Fine, my previous thought was considering diameters and drivers size in "cm" (not inches) so I slipped up.....
You where right about chipboard cabs, GM in this post 1238 suggested bottom and the two corner sides in case of corner loaded BIB.
Do you think the internal baffle should be made of chipboard too?
Thanks.
Ciao.Fab.
Scottmoose said:
Fine, my previous thought was considering diameters and drivers size in "cm" (not inches) so I slipped up.....
You where right about chipboard cabs, GM in this post 1238 suggested bottom and the two corner sides in case of corner loaded BIB.
Do you think the internal baffle should be made of chipboard too?
Thanks.
Ciao.Fab.