Ah yes, the Accuhorn 175. Dunno, to be honest. I haven't seen any good pictures of it, which show a mouth or any detail. The 125 initially looks like an inverted BIB, but in fact, from some shots I found a while ago, appears to be a BVR design.
If it's a dipole, then the drivers must be internally partitioned off from each other, or the rediation from the rear unit, being 180 degrees out of phase with that from the front, would simply cancel out. If they're not partitioned off from each other, then they're actually bipoles, with the drivers running in-phase. In which case, they could have a central expansion upward (or downward) with an additional sloping baffle for the rear unit. My only concern about that is the BIB is a corner horn, and needs the reflection boundary conditions to supress ripple, and you can't do that with bipole or dipole designs. Anyone know of any better shots of these things?
If it's a dipole, then the drivers must be internally partitioned off from each other, or the rediation from the rear unit, being 180 degrees out of phase with that from the front, would simply cancel out. If they're not partitioned off from each other, then they're actually bipoles, with the drivers running in-phase. In which case, they could have a central expansion upward (or downward) with an additional sloping baffle for the rear unit. My only concern about that is the BIB is a corner horn, and needs the reflection boundary conditions to supress ripple, and you can't do that with bipole or dipole designs. Anyone know of any better shots of these things?
Scott,
What would happen if these are dipole bibs, as in two separate enclosures put back to back, if they were placed near a corner? Would the driver facing the corner cause problems in some way?
You may have touched on this and I was to dense to catch it.
Also I wonder what the result would be if you did have two BIB's connected back to back with one firing up and the other down?
One thing I will say about these in the picture, they're well executed, very tastefully done.
Rick
What would happen if these are dipole bibs, as in two separate enclosures put back to back, if they were placed near a corner? Would the driver facing the corner cause problems in some way?
You may have touched on this and I was to dense to catch it.
Also I wonder what the result would be if you did have two BIB's connected back to back with one firing up and the other down?
One thing I will say about these in the picture, they're well executed, very tastefully done.
Rick
>>> Also I wonder what the result would be if you did have two BIB's connected back to back with one firing up and the other down?
That sounds interesting. Any of the usual BIB drivers could be used but a double BIB using 4" drivers like the Fostex 127 or TB Bamboo could be rather room friendly. They are so thin they could litterally be placed side by side (one forward one backward) glued and screwed together.
Hmmmm....
That sounds interesting. Any of the usual BIB drivers could be used but a double BIB using 4" drivers like the Fostex 127 or TB Bamboo could be rather room friendly. They are so thin they could litterally be placed side by side (one forward one backward) glued and screwed together.
Hmmmm....
Whilst talking about dipole BIBs and even dual BIBs I have wondered at the possibility of building two BIB towers side by side, maybe one forward and one backward and maybe, as was mentioned, one up and one down with something akin to an Oris horn mounted between them at the right ear height. If this was possible it would allow maybe half of the horn to be buried between the two BIBs and may well look better than trying to mount a horn on the front of the speaker in a single BIB. Any thoughts on this Scottmoose or GM or anybody else who may have an opinion.
A happy new year to you all and may the thinkinking continue. Be nice to be able to afford 'to do' as well!!
jamikl
A happy new year to you all and may the thinkinking continue. Be nice to be able to afford 'to do' as well!!
jamikl
Rick J. B. said:
see Scott's designs Harvey/Bruce (and no doubt further progeny) - a long thread, with some interesting developments.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=85156
so many designs, so little time
I know that feeling.
Rick: BVR = Big Vent Reflex. You know how most domestic 'horns' feature a small chamber, and a long gradually flaring path length?
A BVR turns this on its head. It has a very large chamber, coupled to a short, rapidly flaring horn (or to be more accurate, waveguide). In technical operation their a reflex box with huge, expanding vents.
Pushing a dipole against a wall is a tricky one -you'll get lots of early reflections, and increase the likelihood of the rear radiation cancelling out that from the front. It's not as bad as some would have you believe, but it's difficult to get going right. A couple of feet at least is a good idea between cabinet and rear wall.
A way of doing this would be to design two unfolded ML TQWTs in the same cabinet, with drivers placed at 50% line length. Alternatively, an inverted BIB, deepened so that a second expansion at the rear could take place, both joining at the top and flaring downward, and then use the plinth to adjust the cabinet height and partially short the output CSA. Castle did something similar with their Harlech / Harlech S2 and Howard S3 designs I believe. Just a fair bit smaller. That would have to be run bipole though rather than dipole. Not that that's a problem: bipole is great.
Rick: BVR = Big Vent Reflex. You know how most domestic 'horns' feature a small chamber, and a long gradually flaring path length?
A BVR turns this on its head. It has a very large chamber, coupled to a short, rapidly flaring horn (or to be more accurate, waveguide). In technical operation their a reflex box with huge, expanding vents.
Pushing a dipole against a wall is a tricky one -you'll get lots of early reflections, and increase the likelihood of the rear radiation cancelling out that from the front. It's not as bad as some would have you believe, but it's difficult to get going right. A couple of feet at least is a good idea between cabinet and rear wall.
A way of doing this would be to design two unfolded ML TQWTs in the same cabinet, with drivers placed at 50% line length. Alternatively, an inverted BIB, deepened so that a second expansion at the rear could take place, both joining at the top and flaring downward, and then use the plinth to adjust the cabinet height and partially short the output CSA. Castle did something similar with their Harlech / Harlech S2 and Howard S3 designs I believe. Just a fair bit smaller. That would have to be run bipole though rather than dipole. Not that that's a problem: bipole is great.
Okay, now that I know what you guys were referencing I most definitly DO find these designs interesting.
That said I've run across designs that appear to be similar but very well maybe very different from one another.
I'm assuming that all of these are called a dbl horn or whatever.
First there's the Son of Frugal.
Then there's Onur Ilkorur's Double horn for the 206E
And then there's the Cain & Cain double Ben.
Now, what do these designs have in common, or how are they different?
Visually they appear to be similar but scientifically are they similar?
I really find the appearance of these intriguing. If executed well as the Cain & Cain Dbl Ben's were they have a high coolness factor!
Rick
That said I've run across designs that appear to be similar but very well maybe very different from one another.
I'm assuming that all of these are called a dbl horn or whatever.
First there's the Son of Frugal.
An externally hosted image should be here but it was not working when we last tested it.
Then there's Onur Ilkorur's Double horn for the 206E
An externally hosted image should be here but it was not working when we last tested it.
And then there's the Cain & Cain double Ben.
An externally hosted image should be here but it was not working when we last tested it.
Now, what do these designs have in common, or how are they different?
Visually they appear to be similar but scientifically are they similar?
I really find the appearance of these intriguing. If executed well as the Cain & Cain Dbl Ben's were they have a high coolness factor!
Rick
You know another thing I've often wondered about, indeed have been close to action upon, is the fact that most horns or horn related designs have angular, sometimes awkward bends and folds. Wouldn't there be a benefit from smoothing, or curving those bends and folds?
I'm probably all wet, but when air is forced through an enclosure and it meets with sharp edges and blunt angular turns, isn't there a sort of turbulence or disruption of flow that could degrade the sound coming out of the enclosures mouth?
I know on my next set of BIB's for the DX-3's I'm going to try a couple of things after I've mocked them up to check the performance of the dimensions.
There's 4 things I thought I'd try.
Make they interior smooth, even finished with varnish and waxed.
At the bottom where the turn is made, build in a smooth curve instead of the air slamming into the bottom and then going up to the mouth at the top.
Also the bottom edge of the interior baffle would be rounded.
As would the edge of the mouth at the top where air exits the enclosure.
Below is a crude sketch of what I've envisioned.
I'm probably all wet, but when air is forced through an enclosure and it meets with sharp edges and blunt angular turns, isn't there a sort of turbulence or disruption of flow that could degrade the sound coming out of the enclosures mouth?
I know on my next set of BIB's for the DX-3's I'm going to try a couple of things after I've mocked them up to check the performance of the dimensions.
There's 4 things I thought I'd try.
Make they interior smooth, even finished with varnish and waxed.
At the bottom where the turn is made, build in a smooth curve instead of the air slamming into the bottom and then going up to the mouth at the top.
Also the bottom edge of the interior baffle would be rounded.
As would the edge of the mouth at the top where air exits the enclosure.
Below is a crude sketch of what I've envisioned.
An externally hosted image should be here but it was not working when we last tested it.
Terry's double BENs were my inspiration for Harvey, Iris & Bruce (the three BVR double horns I designed with Dave, and which go under the 'Spawn of...' banner). I had seen Onur's 206 box before I designed them, but, hand on heart, at the time I'd completely forgotten about it. It's a great box though.
To the best of my knoweldge Terry's BENs are not BVR cabinets, but long-path horn designs.
BVR is an interesting concept, though not often used. It's best considered as a reflex cabinet though, albeit with huge vents, rather than a horn as such.
Smoothing the airflow in a BIB is risky. The LF, which is what we're really after, isn't particularly fussy about angles: the wavelengths are too long. However, the higher frequencies (which we don't want coming out of the terminus if we can avoid it) hate sharp angles, so in this case, the sharper the better, as it helps cut down on the HF leakage. Same reason we put a layer of damping on the base, or use a very lossy material for the base -it helps absorb the HF we haven't been able to clobber by either lining the front of the internal baffle and one wall above the driver, or stuffing the same place. Hopefully we should be able to absorb it, but theory and practice... ;-)
To the best of my knoweldge Terry's BENs are not BVR cabinets, but long-path horn designs.
BVR is an interesting concept, though not often used. It's best considered as a reflex cabinet though, albeit with huge vents, rather than a horn as such.
Smoothing the airflow in a BIB is risky. The LF, which is what we're really after, isn't particularly fussy about angles: the wavelengths are too long. However, the higher frequencies (which we don't want coming out of the terminus if we can avoid it) hate sharp angles, so in this case, the sharper the better, as it helps cut down on the HF leakage. Same reason we put a layer of damping on the base, or use a very lossy material for the base -it helps absorb the HF we haven't been able to clobber by either lining the front of the internal baffle and one wall above the driver, or stuffing the same place. Hopefully we should be able to absorb it, but theory and practice... ;-)
Kerfcore is great stuff though a little pricey.
Good ol bending ply works well also.
Of course you could always go old school and simply kerf it your self. Might have to make a trial run or two on some scrap to get the kerf widths right but once you did it'd be far cheaper.
Last time I checked you could get shop grade birch or maple for about $35 a sheet. Of course I can get A2 birch for about $60 right now if I decided not to veneer.
Also your Metronomes looked sharp! How's the bass response been on them?
Rick
Scottmoose said:
So were Terry's Dbl Bens kind of a pair of Jericho horns joined at the head or what?
Also are the Frugal Jr's the same theory as Onur's?
How do you think that type of speaker would perform bass wise Scott?
So I guess my smoothing ideas are counterproductive huh. Shoot I thought I might be on to something.
Oh well.
Rick
Double BIBs etc
I don't think I'm hijacking this thread which appears to be about variations on a BIB. I have attached very rough sketches about what I was thinking in my previous post and would appreciate any comments. Looking to cross from the BIBs to the round horn anywhere between 150Hz and 300 Hz. jamikl
I don't think I'm hijacking this thread which appears to be about variations on a BIB. I have attached very rough sketches about what I was thinking in my previous post and would appreciate any comments. Looking to cross from the BIBs to the round horn anywhere between 150Hz and 300 Hz. jamikl
Attachments
Jamikl, that's a very interesting design. It would certainly look impressive.
If you're going to cross to the Oris horn around 100hz, which makes sense I think. Were you thinking of using smaller woofers in the BIB's?
Scott would be the guy to ask about this of course.
You know the more I've thought about it the more I like the idea of siamese BIB's, one firing up and one down. Some of the smaller drivers that call for a narrow cabinet might be the best choice from a size & weight stand point. I'd build the cabinet to where the two enclosures shared an inner wall instead of doubling the material up.
Rick
If you're going to cross to the Oris horn around 100hz, which makes sense I think. Were you thinking of using smaller woofers in the BIB's?
Scott would be the guy to ask about this of course.
You know the more I've thought about it the more I like the idea of siamese BIB's, one firing up and one down. Some of the smaller drivers that call for a narrow cabinet might be the best choice from a size & weight stand point. I'd build the cabinet to where the two enclosures shared an inner wall instead of doubling the material up.
Rick
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.