here is the sketch... plans are non complete, but enough to build one. Mail me if you want one
The volume of the CC will not provide enough loading to support the cone at higher volumes. This design woukd be good for low level listening but cannot provide cone control at anything approaching true live listening levels.
ron
The volume of the CC will not provide enough loading to support the cone at higher volumes. This design woukd be good for low level listening but cannot provide cone control at anything approaching true live listening levels.
ron
Just remembered -one of the ideas I was fooling with when coming up with ideas fr the 207 etc. had a chamber volume about 1/2 of the first pass design above. Shorter path-length, larger mouth area. Not quite as much extension, but there you go. Given the 126 version has considerably more than anticipated, and remains perfectly in control even at high SPLs, I imagine it will perform better in real life than on the sim.
With these BVR designs, the filter chamber is deliberately under-damped; it's matching it to an over-damped horn that's the trick, as Greg points out elsewhere. The first pass design above probably doesn't achieve this as well as it might, for which the fault is entirely mine and I hang my head in shame. For reference this is the one with the ~ 1/2 size chamber that I dug out. It's not very refined as these were only quick sims I made when roughing out ideas, but it could offer some potential. Unfortunately, it's a little wider than the other -11 inches rather than 9.25 (internal).
With these BVR designs, the filter chamber is deliberately under-damped; it's matching it to an over-damped horn that's the trick, as Greg points out elsewhere. The first pass design above probably doesn't achieve this as well as it might, for which the fault is entirely mine and I hang my head in shame. For reference this is the one with the ~ 1/2 size chamber that I dug out. It's not very refined as these were only quick sims I made when roughing out ideas, but it could offer some potential. Unfortunately, it's a little wider than the other -11 inches rather than 9.25 (internal).
Attachments
Scottmoose said:
I'm trying to envision WAF on this design.
Tall? It's already way tall. 70", 80", it's all about the same. (80" would probably get reinforcement from my ceiling
)Wide? You suggested doubled side panels, which would add an extra 2-3" to the width, for a total of 13-14". That's still a "small" footprint and might pass WAF. (Not a high passing grade, but pass nonetheless. It's certainly no stinkin' coffee-cup sized little black box
)16" wide external, and I think my wife would bury me in one of them.
But thanks for the great work! It's really tempting. Could be my winter project.
johninCR said:
Good question. Yes, is the answer. Something I'll have to look into at some point. There's pressure differences too, with the lower mouth seeing a greater reflection boundary condition than the upper. Experience suggests it's not really an issue though -the 126 sounds beautifully ballanced even at high volumes -for an impartial view, see Steve's write-up of our recent (& very enjoyable) Fostex and tube amp bash: http://web.mac.com/scress1958/iWeb/Steves_Tube_Trials/FostexFest.html
The ripple at ~ 100Hz in the 207 horn is actually the upper cut-off of the horn. It's more a point of view than anything else -some designs go for a wide-bandwidth of operation, some a narrow. This, and the 126, are a relatively narrow bandwidth designs, and operate in electrical terms like reflex enclosures below this frequency, down to their lower cut-off. This sort of thing is much more common in PA and Arena horns I believe.
Regards
Scott
Great comparative review in that link, thanks. I think you now understand why one of my pairs of 108's will always be on some kind of OB. Nick can probably even get those OB's to a significantly higher level with refinement in his baffles. I just have to get the curiosity out my system regarding horns before I dive exclusively into OB's. A set of the metronomes sounds perfect for an eventual bedroom system, and I'm a willing guinea pig for your double horn for one of my pairs of 206's (limited output???, mine jammed on OB).
It's basically the same as the 126 cabinet. However, I've got a small CC, long pathlength version of all 3 enclosures in the works as well, which will probably suit the sigma better, so you might want to wait for that one. It might take a little while to get drawn though, as we're concentrating on getting the intermediate & large BVR cabinets done first.
Regarding these larger developments of the current BVR theme, I might as well take this opportunity to let you all know what's going on. Iris BVR v1.0 for the FE166/7E & 168ESigma; and Bruce BVR v1.1 for the FE206/7E & 208ESigma are with Dave, and they will be the next cabinets to appear. I also want to publically thank Dave, not only for all his help & enthusiasm, but for kicking me into life again with these larger variations (You might be surprised though at how little the footprint increases -although they're not small, they aren't outrageously proportioned either). I also want to thank Martin & Greg for their advice & constructive criticism in our email conversations.
After some reflection, I decided I wanted to make some major alterations to Bruce, as seen a couple of pages back, as I wasn't entirely happy with the aesthetics or the performance for the cabinet size. That's my fault I hasten to add, not a reflection upon Dave's amazing CAD ability. The folding scheme will be recycled elsewhere however, so v1.0 was still very useful. So you know what to expect, effectively, both Iris & Bruce are now scaled versions of Harvey; & further developments on the big vent reflex enclosure theme. Although technically they are not horns, they do offer an interesting hybid between the two cabinet types -the extension & relative simplicity of a reflex cabinet but with the coupling to a large amount of air that a horn provides. Once these are complete, the more complex 'proper' horn versions (though I'm toying with the idea of using the Nagaoka stage expansion for at least one of them), will make an appearance.
Regards to all
Scott
Regarding these larger developments of the current BVR theme, I might as well take this opportunity to let you all know what's going on. Iris BVR v1.0 for the FE166/7E & 168ESigma; and Bruce BVR v1.1 for the FE206/7E & 208ESigma are with Dave, and they will be the next cabinets to appear. I also want to publically thank Dave, not only for all his help & enthusiasm, but for kicking me into life again with these larger variations (You might be surprised though at how little the footprint increases -although they're not small, they aren't outrageously proportioned either). I also want to thank Martin & Greg for their advice & constructive criticism in our email conversations.
After some reflection, I decided I wanted to make some major alterations to Bruce, as seen a couple of pages back, as I wasn't entirely happy with the aesthetics or the performance for the cabinet size. That's my fault I hasten to add, not a reflection upon Dave's amazing CAD ability. The folding scheme will be recycled elsewhere however, so v1.0 was still very useful. So you know what to expect, effectively, both Iris & Bruce are now scaled versions of Harvey; & further developments on the big vent reflex enclosure theme. Although technically they are not horns, they do offer an interesting hybid between the two cabinet types -the extension & relative simplicity of a reflex cabinet but with the coupling to a large amount of air that a horn provides. Once these are complete, the more complex 'proper' horn versions (though I'm toying with the idea of using the Nagaoka stage expansion for at least one of them), will make an appearance.
Regards to all
Scott
Cool Scottmoose!
I'll wait for them. I'll decide then, whether to go for fe108's or the 168ez's. You're doing an awesome job by the way! I truly appreciate it.
Hey, I was wondering if it were remotely possible to get a set of basic parameters with diagrams explaining how you come to the designs and how to design a horn speaker. Step by step sort of thing. What to look for in a chassis etc. Horn design for dummies. A set of parameter like for BIB's maybe. For people like me that are interested in the design aspect but simply don't know where to start. I know it will be impossible to simplify because of the maths.... but maybe it might stop me asking dumb questions. I know there is a search function but threads over 1000 entries are quite long. I'm very happy to read them mind....
Gotta say the most fun for me is reading all this stuff and researching which designs to do. We don't have an enormous amount of room so I have to choose which boxes I want carefully or 'W' might just kick my @#$. Especially if I make them and they look ordinary.
Cheers Stroop
I'll wait for them. I'll decide then, whether to go for fe108's or the 168ez's. You're doing an awesome job by the way! I truly appreciate it.
Hey, I was wondering if it were remotely possible to get a set of basic parameters with diagrams explaining how you come to the designs and how to design a horn speaker. Step by step sort of thing. What to look for in a chassis etc. Horn design for dummies. A set of parameter like for BIB's maybe. For people like me that are interested in the design aspect but simply don't know where to start. I know it will be impossible to simplify because of the maths.... but maybe it might stop me asking dumb questions. I know there is a search function but threads over 1000 entries are quite long. I'm very happy to read them mind....
Gotta say the most fun for me is reading all this stuff and researching which designs to do. We don't have an enormous amount of room so I have to choose which boxes I want carefully or 'W' might just kick my @#$. Especially if I make them and they look ordinary.
Cheers Stroop
Scottmoose said:
I for one am pretty keen to see the fe108e sigma version, since I must replace the Buschorns sometime soon and the doublehorn will likely fit my situation (no real corners) better than the frugel, tempting though the latter is on the grounds of sheer elegance.
I know you are busy with the BVRs, and recognize that you may even have some sort of life outside this forum (oh no, wait - more than 1800 posts, average 3 1/4 plus per day - cancel the having a life remark), so don't want to be pushy. This is more just to let you know that interest hasn't flagged out here.
Regards.
Aengus
I for one am pretty keen to see the fe108e sigma version, since I must replace the Buschorns sometime soon and the doublehorn will likely fit my situation (no real corners) better than the frugel, tempting though the latter is on the grounds of sheer elegance.
I know you are busy with the BVRs, and recognize that you may even have some sort of life outside this forum (oh no, wait - more than 1800 posts, average 3 1/4 plus per day - cancel the having a life remark), so don't want to be pushy. This is more just to let you know that interest hasn't flagged out here.
Regards.
Aengus
Life? What's that? I gave up on that when I started my doctorate; this is one of the things I do for relaxation. And if it's of any benefit or use to other people, then that's all I could wish for, or more.
The BVRs are just about sorted now. Iris is now complete. Basic layout is the same as Harvey, and she actually shares the same height and depth, while being only 1.25in wider. With the FE166E, she gains some extension and response should be even flatter than Harvey. I'm currently checking other drivers. Shifts more air too, obviously, and will play louder. Bruce is currently in the works for drawing up. Once we've got all three CAD designs done, we'll get a document similar to the Frugels sorted for them -I've got the draft introduction just about finished, so it shouldn't be too long now.
I gave up on that when I started my doctorate; this is one of the things I do for relaxation. And if it's of any benefit or use to other people, then that's all I could wish for, or more. The BVRs are just about sorted now. Iris is now complete. Basic layout is the same as Harvey, and she actually shares the same height and depth, while being only 1.25in wider. With the FE166E, she gains some extension and response should be even flatter than Harvey. I'm currently checking other drivers. Shifts more air too, obviously, and will play louder. Bruce is currently in the works for drawing up. Once we've got all three CAD designs done, we'll get a document similar to the Frugels sorted for them -I've got the draft introduction just about finished, so it shouldn't be too long now.
Bruce V.1.1 BVR design is now complete. Dave got his usual, superb finalised CAD drawings to me today. Same height as Harvey and Iris, a little wider, a little deeper (not much). Should be solid to 30Hz in-room. Excursion is pretty good -stays well below Xmax. The BVR family is now complete; we'll get some kind of page or downloadable pdf for them sorted out at some point soon. Like the Frugels, feedback from builder's will be appreciated, so we can refine the designs based upon the requests.
Small CC double horns are currently in the works. They're rather different to the BVRs...
Small CC double horns are currently in the works. They're rather different to the BVRs...