who's who
yep, along with the various BD-pipes posted on the tweeter of the week, and a few others
The Daline's are now serving quite well in H/T system, after the first taste of SET amp and FR drivers, I've never looked back.
Funniest thing; after selling my first pair of Buschorns a few weeks back ( to a very nice home), I regained title to a pair of custom Heil AMT/Fostex FW227 2-ways I built several years back.
They're much more visually imposing than the 'horns, and while chatting with me during some work on a pair of bi-pole Fostex 127 MLTL for Dave, my wife says
"Honey, I miss those other speakers, they were so cute. Could you please build another pair? I'll pay for the parts" ( FE108E Sigma)
How can I say no to that?
Ropie said:
yep, along with the various BD-pipes posted on the tweeter of the week, and a few others
The Daline's are now serving quite well in H/T system, after the first taste of SET amp and FR drivers, I've never looked back.
Funniest thing; after selling my first pair of Buschorns a few weeks back ( to a very nice home), I regained title to a pair of custom Heil AMT/Fostex FW227 2-ways I built several years back.
They're much more visually imposing than the 'horns, and while chatting with me during some work on a pair of bi-pole Fostex 127 MLTL for Dave, my wife says
"Honey, I miss those other speakers, they were so cute. Could you please build another pair? I'll pay for the parts" ( FE108E Sigma)
How can I say no to that?
Re: who's who
Good work! The Dalines are still down on my list of possible future diy sealed cabinet speakers, along with some Jordan TLs and the ZHorn Heruka. I used to have some TLs that were unfortunately burnt out by a rogue valve buffer; they had amazing bass but the Buschhorns are much better in terms of detail, soundstage and imaging.
Well, it would be rude not to accept! My GF has the same opinion of my Bhorns. They are very elegant speakers and that is part of the reason I chose them - I can have them a metre into the room without too many complaints!
chrisb said:
Good work! The Dalines are still down on my list of possible future diy sealed cabinet speakers, along with some Jordan TLs and the ZHorn Heruka. I used to have some TLs that were unfortunately burnt out by a rogue valve buffer; they had amazing bass but the Buschhorns are much better in terms of detail, soundstage and imaging.
Well, it would be rude not to accept! My GF has the same opinion of my Bhorns. They are very elegant speakers and that is part of the reason I chose them - I can have them a metre into the room without too many complaints!
Ropie said:
Yep that Chris... the 1197 BD-Pipes actually launched him on his current FR journey... latest news is that the WAF of the 108ES Buschorns is so high that his wife is buying him another pair of drivers so she can have them back in the living room.
They may actually end up being modded for a larger mouth (more consistent horn for better bass).
dave
Buschhorn modifications
Hello
I am about to build a pair of Buschhorn IIs using FE108ESigmas and have some questions. I've read through this and other forums (fora?) on the BHs and don't think I've seen this discussed - but if it has been, I apologize for redundancy and would appreciate a pointer.
What I consider doing are some modifications, as in the drawing. Black lines are the original; dotted black to be removed; red to be added; dotted red, placement TBD by experiment; curved red to be the closest shape I can get out of 1/8" plywood to an expanding curve.
The rationale for the slanted top is that the original was made for a physically smaller speaker and must lead to early reflections back at the FE108s. I'd move the top up by 3cm so the CC is now square. The slant is just because I don't need all that space back there (and to discourage my wife from putting stuff on the top.
Comments appreciated. (and I don't know if I managed to attach the image - newbie toothcutting going on
Hello
I am about to build a pair of Buschhorn IIs using FE108ESigmas and have some questions. I've read through this and other forums (fora?) on the BHs and don't think I've seen this discussed - but if it has been, I apologize for redundancy and would appreciate a pointer.
What I consider doing are some modifications, as in the drawing. Black lines are the original; dotted black to be removed; red to be added; dotted red, placement TBD by experiment; curved red to be the closest shape I can get out of 1/8" plywood to an expanding curve.
The rationale for the slanted top is that the original was made for a physically smaller speaker and must lead to early reflections back at the FE108s. I'd move the top up by 3cm so the CC is now square. The slant is just because I don't need all that space back there (and to discourage my wife from putting stuff on the top.
Comments appreciated. (and I don't know if I managed to attach the image - newbie toothcutting going on
Attachments
Buschhorn modifications
Aengus,
I cannot comment on the effect of CC modifications on the change in lowpass characteristics of the horn although the slanted top to prevent the Buschhorn to become an extension of a flowervase is just brilliant
The rounding of the corners in the folded horn are IMO obsolete and were part of the Buschhorn Mk1 (you are referring to the Mk2 drawings here) plans. The lower frequencies do not mind too much travelling around these angles although our brains think it is very hard for them to make all those turns. At least make sure that you fill all the open spaces with fine sand to prevent resonancies.
Aengus,
I cannot comment on the effect of CC modifications on the change in lowpass characteristics of the horn although the slanted top to prevent the Buschhorn to become an extension of a flowervase is just brilliant
The rounding of the corners in the folded horn are IMO obsolete and were part of the Buschhorn Mk1 (you are referring to the Mk2 drawings here) plans. The lower frequencies do not mind too much travelling around these angles although our brains think it is very hard for them to make all those turns. At least make sure that you fill all the open spaces with fine sand to prevent resonancies.
I agree WRT to the shape of the horn; it takes away some of the 'boxy' character (although the original BH shape isn't visually appalling at all IMHO; but I also quite like more radical approaches, like this).
If I were you I would leave the CC size variable, so that you can tune it to match your room acoustics. You can always make it smaller using small sand-filled bags and a piece of wood.
For my room and equipment, the smallest possible CC definitely works best.
Best regards,
Oliver
If I were you I would leave the CC size variable, so that you can tune it to match your room acoustics. You can always make it smaller using small sand-filled bags and a piece of wood.
For my room and equipment, the smallest possible CC definitely works best.
Best regards,
Oliver
Thank you all for the helpful response. A couple of questions and comments:
DocLorren, you said:
I can agree without being immodest, since the idea originated before my time. What I was thinking of with the curves was more trying to maintain a constant expansion characteristic; I don't know how critical this is, though.
coredump , the Rethm horns are great - thanks for the link. Think I'll stick to linear stuff for my first one, though I've been spending some time trying to come up with a way of cold-molding (boatbuilding technique, good for compound curves) a circular cross-section horn. The problem is creating the mold, and CNC 3-axis milling machines are a bit beyond my budget.
Planet10, I'd be pleased to see your (and chrisb's) variations on this theme. Do you know if he is planning such modifications on the new one? And if ChrisB has any tips on how to get one's wife to buy the drivers? Heck, I'd even settle for approve the drivers.
Regards.
DocLorren, you said:
and:
I can agree without being immodest, since the idea originated before my time.
What I was thinking of with the curves was more trying to maintain a constant expansion characteristic; I don't know how critical this is, though.coredump , the Rethm horns are great - thanks for the link. Think I'll stick to linear stuff for my first one, though I've been spending some time trying to come up with a way of cold-molding (boatbuilding technique, good for compound curves) a circular cross-section horn. The problem is creating the mold, and CNC 3-axis milling machines are a bit beyond my budget.
Planet10, I'd be pleased to see your (and chrisb's) variations on this theme. Do you know if he is planning such modifications on the new one? And if ChrisB has any tips on how to get one's wife to buy the drivers? Heck, I'd even settle for approve the drivers.
Regards.
AengusM said:
If i can keep him from chomping at the bit long enuff (he did just get a set of the FE127 bipole references done and making tunes), for his next FE108ESs (his wife liked the WAF of the B-Horns so much, she is instisting on another pair -- the driver cost is even coming out of her budget
) we are going to extend the (idea of) B-Horns somewhat to try to eliminate voids, create a less tube-like compression cahmber, and most importantly extend the horn mouth to make it much closer to a consistent horn, instead of a TL/Horn hybrid (i'm using MJK terminology here).I have a scheme whereby i think i can get triple the horn mouth area, not destroy the footprint much, and make the box more interesting looking -- all at the same time. I need to generate an optimum FE108ES horn and fold it into the box. It will be more challenging to build thou.
dave
Buschorn
Aengus: the world can't be this small, we should definitely get together - possibly at the new home of my recently relocated 'horns.
(Unless you've already heard them)
As Dave mentioned a few posts ago, we're jointly working on a "morpho- vultion" to the B-horn edesign , that while retaining some of the geometry of the fold, has a few of significant differences.
We're still working on the details, but might have something to share in the near future, and yes they will be "slightly" hard to build than the stock design.
Aengus: the world can't be this small, we should definitely get together - possibly at the new home of my recently relocated 'horns.
(Unless you've already heard them)
As Dave mentioned a few posts ago, we're jointly working on a "morpho- vultion" to the B-horn edesign , that while retaining some of the geometry of the fold, has a few of significant differences.
We're still working on the details, but might have something to share in the near future, and yes they will be "slightly" hard to build than the stock design.
Piero,
are you sure about the cap value? Fostex recommends such big values normally to go with their bigger FR drivers. 1.5uF into 8ohms leads to a -3db point at 13250 Hz -- far too low for a 108.
I tried a few possible variants:
* cap & resistor before tweeter only
* 1st order low pass before 108, 2nd order high pass before tweeter
* same as above, only with 1st order high pass before tweeter
In short: a T90A with a 0.22uF cap and a 14 ohm resistor in series works second best for me. Saying that, I also have to mention that I use impedance linearization (0.47uF+8.2ohms parallel to the 108) and the horns are about 20cm from the back wall; this probably leads to some reflections in the higher frequencies.
The best sound (to my ears) comes without a tweeter, as otherwise I feel the speakers lose coherence and 'that certain charm', which I favor over a greater absolute bandwidth.
Best regards,
Oliver
are you sure about the cap value? Fostex recommends such big values normally to go with their bigger FR drivers. 1.5uF into 8ohms leads to a -3db point at 13250 Hz -- far too low for a 108.
I tried a few possible variants:
* cap & resistor before tweeter only
* 1st order low pass before 108, 2nd order high pass before tweeter
* same as above, only with 1st order high pass before tweeter
In short: a T90A with a 0.22uF cap and a 14 ohm resistor in series works second best for me. Saying that, I also have to mention that I use impedance linearization (0.47uF+8.2ohms parallel to the 108) and the horns are about 20cm from the back wall; this probably leads to some reflections in the higher frequencies.
The best sound (to my ears) comes without a tweeter, as otherwise I feel the speakers lose coherence and 'that certain charm', which I favor over a greater absolute bandwidth.
Best regards,
Oliver
Mounting the Fostexes
OK, I got the bits and pieces cut last weekend. Won't be able to work on them again until next week, but am considering how to make the hole for the speakers. Options are to use a drill-press and a fly-cutter (have to buy a fly-cutter and borrow a drill-press), or spend some time building a jig for the router. Anyway, once that's done I'll be able to mount the drivers, which brings up some questions:
As shipped, the drivers have a sort of felt gasket on the front: is this to be placed behind the flange when they're actually mounted?
Should I rout out a recess and try to flush-mount them, or just surface mount them (presumably on top of the gasket in either case)?
What have you guys done by way of fixing them to the cabinet? There's not a lot of clearance for T-nuts or similar. I consider counterboring the back of the bolt holes and epoxying in some hexnuts - but would be happy with a simpler solution.
Finally: non-magnetic fixing bolts (brass, ss)? Or does it matter.
Once again, thanks for the input - this board is a wonderful resource for me (and those like me) floundering through the first set of speakers.
OK, I got the bits and pieces cut last weekend. Won't be able to work on them again until next week, but am considering how to make the hole for the speakers. Options are to use a drill-press and a fly-cutter (have to buy a fly-cutter and borrow a drill-press), or spend some time building a jig for the router. Anyway, once that's done I'll be able to mount the drivers, which brings up some questions:
As shipped, the drivers have a sort of felt gasket on the front: is this to be placed behind the flange when they're actually mounted?
Should I rout out a recess and try to flush-mount them, or just surface mount them (presumably on top of the gasket in either case)?
What have you guys done by way of fixing them to the cabinet? There's not a lot of clearance for T-nuts or similar. I consider counterboring the back of the bolt holes and epoxying in some hexnuts - but would be happy with a simpler solution.
Finally: non-magnetic fixing bolts (brass, ss)? Or does it matter.
Once again, thanks for the input - this board is a wonderful resource for me (and those like me) floundering through the first set of speakers.
If you can sink a hexnut in then T-nuts should fit in fine shouldn't they? Presumably we are talking about these:
http://sunshinefoam.com/pages/29.html
Don't forget to post pictures when they are done I'll be interested to see these.
http://sunshinefoam.com/pages/29.html
Don't forget to post pictures when they are done
I'll be interested to see these.
Absolutely right - those are the things. In my experience they are somewhat larger in diameter than the equivalent thread size hex nut (I'm guessing I'm looking at a number 8 or 10, haven't actually checked) - but I will confirm this. The other issue is that the hexnuts are typically steel (=magnetic) and in close proximity to the driver, so I wondered whether they might affect the driver's magnetic field.
Thank you, Chris. I may take you up on it; in any case I'll give you a call next week when I'm back in town.
On a personal note: hurray, my project (deadline: midnight tonight) looks like it's actually going to make it. Means I can switch back to a normal 50 hour week and get some weekend time in the shop
.T-nuts
With the smaller size drivers, ( 4-6") I've had good success with M4 t-nuts (or even better, threaded inserts) and bolts. Just make sure you layout their footprint if you're back bevelling the mounting baffle or there won't be enough core material for them to anchor.
The problem with commonally available non-ferrous fasteners ( other than stainless) is the torque required to fully seat the foam gaskets can be enough to shear brass or aluminum. It's bad enough when the claws of the T-nut don't fully engage, but when you snap the bolt in a fully anchored fitting, that's a whole 'nother world of hurt.
Slightly OT, but still relating to Fostex drivers ( FE127E) - I've just got a pair of unfolded bipole MLTLs running right now. After fully breaking in the FE108E Sigmas in the Buschorns, I'd forgotten just how "raw" the sound can be with fresh out of the box drivers.
It's not too much of a stretch to understand why someone hearing (brand new) Fostex drivers for the first time might question what the fuss is about. Just spent a lot of time in the building/tweaking amps during the first 3 months of break-in, hopefully your bench system doesn't sound better than upstairs.
With the smaller size drivers, ( 4-6") I've had good success with M4 t-nuts (or even better, threaded inserts) and bolts. Just make sure you layout their footprint if you're back bevelling the mounting baffle or there won't be enough core material for them to anchor.
The problem with commonally available non-ferrous fasteners ( other than stainless) is the torque required to fully seat the foam gaskets can be enough to shear brass or aluminum. It's bad enough when the claws of the T-nut don't fully engage, but when you snap the bolt in a fully anchored fitting, that's a whole 'nother world of hurt.
Slightly OT, but still relating to Fostex drivers ( FE127E) - I've just got a pair of unfolded bipole MLTLs running right now. After fully breaking in the FE108E Sigmas in the Buschorns, I'd forgotten just how "raw" the sound can be with fresh out of the box drivers.
It's not too much of a stretch to understand why someone hearing (brand new) Fostex drivers for the first time might question what the fuss is about. Just spent a lot of time in the building/tweaking amps during the first 3 months of break-in, hopefully your bench system doesn't sound better than upstairs.
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