New horn
Printed From: Speakerplans.com
Category: Plans
Forum Name: New Projects Forum
Forum Description: Forum for new speakerplans projects, in memory of Tony Wilkes, 1953 - 2014
URL: https://forum.speakerplans.com/forum_posts.asp?TID=75903
Printed Date: 26 March 2026 at 7:42pm
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: New horn
Posted By: Steve_B
Subject: New horn
Date Posted: 04 February 2013 at 12:00am
I know you like looking at pictures, so here is one of a horn I am working on which came off the mould today. It is for a 2" exit drive unit and I'm hoping for a 60 x 40ish dispersion. It is 32cm wide by 23cm high which was chosen as a direct fit in to a cabinet I already use. It is also similar to a few horns out there from other manufacturers. I just need some reasonable weather to do some measurements now.
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Replies:
Posted By: mykey-
Date Posted: 04 February 2013 at 1:38am
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Very nice Steve. My favourite colour too. Can we have a profile picture? ------------- BbbBBRAAAAPppBBBBbgushhhhhhhhssshhhhhGrAbRAAAAAAPPPPPp = Dubstep |
Posted By: Steve_B
Date Posted: 04 February 2013 at 12:42pm
| Yeh, I'll put one up when I get the chance, plus some on and off axis response curves. |
Posted By: Timebomb
Date Posted: 04 February 2013 at 12:48pm
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Nice, is the first section conical, then the second section a bit more curved? Is it a kinda 2 stage constant directivity with the second section smoothed to the mouth termination? ------------- James Secker facebook.com/soundgearuk James@soundgear.co.uk www.soundgear.co.uk |
Posted By: VECTORDJ
Date Posted: 04 February 2013 at 12:51pm
| A+ How did you make the plug?? VECTORDJ |
Posted By: Steve_B
Date Posted: 04 February 2013 at 8:08pm
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Here is a side view
The apparent change in flare rate is an illusion caused by
the light. There is a gradual curve as the round throat changes to the oval
mouth. The plug is hand made. I stack disks and use filler. Sanding
and several templates then get me to the required shape. CNC or a 3D printer
would be quicker and more accurate, but at this stage I don’t know if the
design is viable and I have more time than cash. |
Posted By: Lee In Montreal
Date Posted: 04 February 2013 at 9:01pm
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Makes me thing of a good old JBL horn, as used on $35k Paragons or 2395 lenses. Just shorter. Nice work BTW. |
Posted By: Steve_B
Date Posted: 04 February 2013 at 9:47pm
| I hadn't actually considered that, but you're right. I used to use some of the RCF horn/lens assemblies and they had an elliptical mouth. They sounded nice without the lens too. |
Posted By: VECTORDJ
Date Posted: 04 February 2013 at 10:57pm
| Hi, Does the slight curve cause beaming at the top end??? I looked into 3d printing and found it very $. Maybe I was looking in the wrong place. VECTORDJ |
Posted By: ceharden
Date Posted: 04 February 2013 at 11:28pm
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Looks a lot like the 18Sound which I am a big fan of. I think you might be onto a winner! |
Posted By: Steve_B
Date Posted: 05 February 2013 at 12:12am
I'll let you know when I measure them. With a 2" throat the horn won't have much control above 8KHz. I did these as a replacement to us in some cabs I already have which use a design similar to the BMS 2230. It seems to be a generic design as I've seen essentially the same thing done by a number of manufacturers. That obviously set the size of the mouth which is 32cm by 23cm. If everything works to plan I'm looking at about 60 by 40 above 2KHz and a graceful widening (loss of control) as frequency drops down through the crossover frequency which is presently set at 1100Hz
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VECTORDJ wrote:Posted By: Steve_B
Date Posted: 05 February 2013 at 2:37pm
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I managed to do a quick measurement this morning. This was the set up:  The driver is a P.audio BM 750 First a freq response on axis with no eq:  These off axis plots were done with a 1.2KHz hp filter. I didn't measure the angles and just rotated the cab around on the stand.  The yellow plot is about where I was expecting the reasonable limit to be and the white plot is way outside the coverage angle I'm aiming for. I just need some warm weather now to start experimenting.
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Posted By: Dref
Date Posted: 05 February 2013 at 2:51pm
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Hi Steve Looking good as always. What is the color code, looks almost identical to the color of my TVR  The measurements actually looks quite good considering the setup and the driver used. It must be a nice sounding horn.  ------------- A proper build subwoofer will be the only thing in a room that is not shaking. |
Posted By: Steve_B
Date Posted: 05 February 2013 at 6:41pm
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The colour is just one of the standard pigments they stock
where I get my supplies from. It is called golden yellow. I’ll have to check on
the can to see what the code is. I was using it to make a sledge a couple of
weeks back and thought I’d try it on the horns. With regards the response graphs, the most noticeable
anomaly is the dip in response between 2.5KHz and 3KHz. I suspect that this is
caused by reflections off the edge of the cabinet. The flange thickness is
slightly less than the horn the cabinet originally used so it sits back a
little. The width of the cabinet is such that the cross width corresponds to
1.5 wavelengths at about 3KHz. The ripples in response on the white graph look
close to higher harmonics which would confirm my belief. When I get some suitable weather I’ll pack the horn forward
slightly so it is flush and also measure the horn without a baffle. I don’t
remember the rising response above 6.5KHz on previous measurements with this
drive unit so that is something else I need to recheck. Ignoring the dip in response the coverage seems pretty consistent
between 2 and 10KHz. |
Posted By: ceharden
Date Posted: 05 February 2013 at 8:27pm
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Plots look pretty good to me. The big question is how does it sound? |
Posted By: Dref
Date Posted: 05 February 2013 at 9:04pm
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Don't worry about the color code, it was mostly a joke. I wouldn't be able to tell a specific shade of yellow from a photography. I just like the color of your horn What were the distance from the shed? On the picture it looks quite close, but that might just be an illusion. ------------- A proper build subwoofer will be the only thing in a room that is not shaking. |
Posted By: Steve_B
Date Posted: 06 February 2013 at 1:34am
A quick listen using just the left channel from an mp3
player wasn’t ideal, but it wasn’t bad. The plots are important to me, because the fun part is
understanding how these things work. A lot of this would go un-noticed by just
listening.
It is about 2m. I’ve got
quite a big garden so there is nothing behind the microphone and I usually move
further away from the shed especially when measuring lower frequencies. The
weather wasn’t great today though. |
Posted By: Steve_B
Date Posted: 17 February 2013 at 3:06pm
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Just to update. I've slightly reworked the throat and packed the horn forward so it is flush with the front edges of the cabinet.  Plots are at 10 degree increments off axis the yellow is the live plot so is the same as the green
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