I can't see the innards well enough to discern profiles, but if they're like the earlier drawing, then it's a reciprocating flare with the closed down flares (~0 deg) would be on the top and bottom with the wide expanding flares on the sides for a nominally 90 deg H x 60 deg V since it's ~ a square mouth. Note that since its not a constant directivity WG it will at best have this pattern over only a very narrow BW.
GM
GM
Well, I agree it is a little confusing. Using only the external flare profile, one is straight at the throat with pronounce flare at the mouth. The other is heavily flared at the throat and somewhat straight at the mouth.
I'm saying the one with the flare at the throat has more effect than the one with the flare at the end, and the throat flare is therefore the 90deg dispersion, and those throat flares should be on the horizontal.
But, I also confess a degree of doubt.
steve/bluewizard
I'm saying the one with the flare at the throat has more effect than the one with the flare at the end, and the throat flare is therefore the 90deg dispersion, and those throat flares should be on the horizontal.
But, I also confess a degree of doubt.
steve/bluewizard
BlueWizard said:
Actually, as presented you have it backwards if I'm following you in that the flared throat has a faster expansion than the more pipe-like throat, making it more of a WG that will narrow up on axis with increasing frequency while the slow expansion throat combined with the rapid end expansion causes a more uniform pattern over a wider arc than the angle suggests, but when the two are combined they mute each other to some extent, so the wide pattern isn't as wide and the narrow not so narrow.
Note too that the wall angle only controls directivity for F6 WLs < 10^6/(width*angle), so for a 1" throat it can only control WLs > ~16,667 Hz/60 deg or ~11,111 Hz/90 deg, both well above the horn's gain BW, ergo the throat is only acting as a part of a compression horn below these frequencies in these examples.
GM
Thanks everyone for your input - evidently this wasn't as simple a question as I thought. Given that the dispersion characteristics are only applicable over a narrow bandwidth, and given the fact that my ears are older than dirt anyway, I probably wouldn't notice which way it was oriented. 
I'll take Cal's advice and just listen and maybe try to measure it off-axis and see what's up (or down).
I'm leaning toward Kevin's advice too - mount it at 45 degrees, call it a diamond tweeter, and enjoy the best of both worlds. Good call Kevin.
I'll take Cal's advice and just listen and maybe try to measure it off-axis and see what's up (or down).I'm leaning toward Kevin's advice too - mount it at 45 degrees, call it a diamond tweeter, and enjoy the best of both worlds. Good call Kevin.
AJ
So the final guess is to mount it with the nubs vertically, right? I'll have mine Monday.
OT, got one Lil Buddy yesterday (the other's backordered
). Have you listened to yours yet? If so, is there a breakin period? I hooked it up w/o being mounted and just the mid band signal- sounded kinda odd.
Jon
So the final guess is to mount it with the nubs vertically, right? I'll have mine Monday.
OT, got one Lil Buddy yesterday (the other's backordered
). Have you listened to yours yet? If so, is there a breakin period? I hooked it up w/o being mounted and just the mid band signal- sounded kinda odd.Jon
Hi bonjonno
I haven't had the time to do anything but cut new baffles. I'm making a separate baffle for each driver so I easily move them around, mix and match, whatever. They'll just mount to the 2X4 frames in any configuration I want.
Yes, I'm guessing that the nubs should be oriented vertical. It squares (pun) with GM's info and my instincts - whatever that's worth.
Don't put too much stock in what you're hearing from a raw driver sitting on its magnet - it'll change once they're in appropriate baffles/boxes.
I haven't had the time to do anything but cut new baffles. I'm making a separate baffle for each driver so I easily move them around, mix and match, whatever. They'll just mount to the 2X4 frames in any configuration I want.
Yes, I'm guessing that the nubs should be oriented vertical. It squares (pun) with GM's info and my instincts - whatever that's worth.
Don't put too much stock in what you're hearing from a raw driver sitting on its magnet - it'll change once they're in appropriate baffles/boxes.
Here is a possibility. The horns are screw mounted from the front. So, put one one way and the other the other way, listen for a while and see which one you like best, and change the other one to match your preference.
60deg dispersion is still pretty good. I would say that 90deg is very good. Either way they will sound good. I think better than most cone or dome tweeters.
Steve/bluewizard
60deg dispersion is still pretty good. I would say that 90deg is very good. Either way they will sound good. I think better than most cone or dome tweeters.
Steve/bluewizard
Does the plastic seem cheap and flimsy or does it seem solid enough?
I am considering this tweeter/horn combo just like you. I wanted to crossover pretty low tho (1500khz maybe). I know there are more expensive compression tweeters and horns made from metal. What's your take AJ?
TIA,
Godzilla
I am considering this tweeter/horn combo just like you. I wanted to crossover pretty low tho (1500khz maybe). I know there are more expensive compression tweeters and horns made from metal. What's your take AJ?
TIA,
Godzilla
Godzilla,
I really don't know what to expect from off-the-shelf horns, but here's my experience so far. I've only had 4 different horns/WGs in hands, so I can't speak beyond those.
********************************************
DDS ENG90 -
Fiberglass waveguides. On my set, the ID of the WGs is beautiful until you get to the throat. One of them has a small gouge about 3/8 inch long that runs at an angle to the throat and breaks out at the face of the mounting flange. The other one had a ~1/16" lip running all the way around the throat/flange intersection. I left the gouge in the one for future work, but I had to carefully sand down the lip on the other one. Both of them required alot of work with a dremel and a carbide burr just to allow a nut to go over the mounting bolt. This was my major complaint - the quality of the OD of these horns just plain sucked. I'm serious about what it took to relieve the areas around the bolt holes. I was very concerned about breaking thru the wall of the horn, and in the end, I still ended up with a non-flat surface for the nut and washer to rest against when they were tightened down. This is just asking for the uneven pressure to crack the flange. Also, I had to elongate the mounting holes to allow the driver to center on the throat. I wasn't thrilled.
********************************************
XT1086 - cast aluminum and very nice.
********************************************
B&C ME10 -
Very nice, quality molded plastic, with nearly a 1/4 inch wall thickness all the way around . It feels a little harder than most ABS I've seen and I'd be careful with the mounting screws and wouldn't try to over-tighten them.
********************************************
PE 12 inch waveguides -
ABS and for 9 bucks I wasn't expecting too much. Throat area was pretty screwed up. Looks like they have a guy with an air grinder sanding off the flash left over from a crappy mold. The upside is that for 9 bucks you can remove the nice brass threaded inserts and make your own mounting flanges for less than you can buy the insert.
In spite of the lousy workmanship on the outside of the ENG90, it's far and away the best thing I've heard so far. And it has the added bonus of being round, so you don't have to stress out wondering which way it goes.
I really don't know what to expect from off-the-shelf horns, but here's my experience so far. I've only had 4 different horns/WGs in hands, so I can't speak beyond those.
********************************************
DDS ENG90 -
Fiberglass waveguides. On my set, the ID of the WGs is beautiful until you get to the throat. One of them has a small gouge about 3/8 inch long that runs at an angle to the throat and breaks out at the face of the mounting flange. The other one had a ~1/16" lip running all the way around the throat/flange intersection. I left the gouge in the one for future work, but I had to carefully sand down the lip on the other one. Both of them required alot of work with a dremel and a carbide burr just to allow a nut to go over the mounting bolt. This was my major complaint - the quality of the OD of these horns just plain sucked. I'm serious about what it took to relieve the areas around the bolt holes. I was very concerned about breaking thru the wall of the horn, and in the end, I still ended up with a non-flat surface for the nut and washer to rest against when they were tightened down. This is just asking for the uneven pressure to crack the flange. Also, I had to elongate the mounting holes to allow the driver to center on the throat. I wasn't thrilled.
********************************************
XT1086 - cast aluminum and very nice.
********************************************
B&C ME10 -
Very nice, quality molded plastic, with nearly a 1/4 inch wall thickness all the way around . It feels a little harder than most ABS I've seen and I'd be careful with the mounting screws and wouldn't try to over-tighten them.
********************************************
PE 12 inch waveguides -
ABS and for 9 bucks I wasn't expecting too much. Throat area was pretty screwed up. Looks like they have a guy with an air grinder sanding off the flash left over from a crappy mold. The upside is that for 9 bucks you can remove the nice brass threaded inserts and make your own mounting flanges for less than you can buy the insert.
An externally hosted image should be here but it was not working when we last tested it.
In spite of the lousy workmanship on the outside of the ENG90, it's far and away the best thing I've heard so far. And it has the added bonus of being round, so you don't have to stress out wondering which way it goes.
Hmm, off axis the difference should be quite audible. What I meant is that in a polar response of this type horn it won't have a 90 x 60 deg pattern, but one that has a mean that will narrow up from ~90 - 60 deg over a wide BW yet only be 90 or 60 deg over a very narrow BW.
For instance, the Altec 511 is listed as 90 x 40 deg and has side walls that are splayed 90 deg, but look at its horizontal response, it wanders around 75 deg for much of its BW and forget it being 90 x 40 in the same BW:
GM
For instance, the Altec 511 is listed as 90 x 40 deg and has side walls that are splayed 90 deg, but look at its horizontal response, it wanders around 75 deg for much of its BW and forget it being 90 x 40 in the same BW:
GM
Attachments
Thanks for the clarification GM - I think. That graph of the 511 is pretty interesting and is not what I would have expected to see.
So what you're saying is that the orientation of this horn is still important if you want to maintain, for instance, the widest possible horizontal coverage, but that the coverage in both axes is frequency dependent and may never actually intersect at 90 X 60?
I think I may need to read a book.
So what you're saying is that the orientation of this horn is still important if you want to maintain, for instance, the widest possible horizontal coverage, but that the coverage in both axes is frequency dependent and may never actually intersect at 90 X 60?
I think I may need to read a book.
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