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Multi-Way Conventional loudspeakers with crossovers

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Old 3rd May 2018, 08:46 PM   #1
Patrick Bateman is offline Patrick Bateman  United States
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One of the things that might not be immediately apparent about the Danley Synergy Horns is that they're quite deep. For instance, here's a pic of the Danley SH50 sitting next to my Gedlee Summas. The width and the height of the Summas is quite large, because that's a fifteen inch waveguide, but the cabinet itself is fairly shallow because the waveguide is 90 degrees. The face of the SH50 is smaller overall than the Summa, but it's quite deep; a 50 degree waveguide is 2.4x as deep as a 90 degree waveguide.

The Lambda Unity Horns had sixty degrees of coverage and the Danley SH-50 has fifty. I don't think this was accidental; narrowing the angle makes things a lot easier in a Unity horn. This is because it can be challenging to get the midrange in a Unity horn to 'meet up' with the tweeter. You can play around with this in Hornresp; you'll see that narrowing the beamwidth raises the output of the tweeter and the midrange.
waveguideDiet1.jpg

For instance, the big QSC waveguide is 13cm deep. That means that it's starting to unload about 654Hz. Which sounds good for a Unity horn, right? We have horn gain down to 654Hz. The problem here is that everything in the horn is unloading near the same frequency:

1) The tweeter is unloading around 1500Hz
2) The horn is unloading around 654Hz
3) The midranges are unloading around 1khz (because the mids are mounted just a few inches from the mouth.)

Now I'm not saying it's impossible to make a Unity horn with a wide beamwidth, just saying it's difficult. If you don't get all the variables JUST right, you're going to have a dip in the midrange. Which is the last place you want it, and it may be geometrically impossible to fix it.
c9vgZuv.jpg

There's a new waveguide out there which may be helpful for the DIY crowd that's dealing with this problem. On the left, is the QSC 15" waveguide. I'd argue it's been one of the best waveguides ever for Unity horn DIYers, right up there with the SEOS 15. It is no longer available. On the right is the "11" x 17" ABS 2" Bolt-On Long Throw Horn 90 x 40 For Many 2" Exit Driver." Yeah, that's a mouthful, I wish they just named it horn-9040 or something catchy.

In the pic, you can see that the mouth of the new horn isn't a whole lot bigger than the venerable QSC...
EU0jdEI.jpg

But flip it over, YOWZA, that thing is deep. 30cm deep to be exact. That'll load your tweeter down to 283Hz and your mids down to about 340Hz.

xOKE0Hs.jpg

The eBay seller "zxpc" advertises this as a 90 x 40 horn. My calculator indicates that this would be a 67.4 x 49.2 IF it was conical. From the profile, you can see that it starts out narrow and goes wide at the mouth. I'd estimate it's about 56 x 40. I'd have to measure it to confirm, I'm just basing this on the measured geometry. If it's 56 x 40, that's an average of 48, or almost identical to the Danley SH-50, SH-64, and SH-46.
kNy6ZH2.jpg

So what's the downside? It sure isn't the price, it's only $40. And the build quality is better than Pyle. One lil' problem, this is a 2" horn, so it's going to need an adapter.

Stay tuned...

Last edited by Patrick Bateman; 8th May 2018 at 05:33 PM. Reason: my original images were replace with forum attachments somehow
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Old 3rd May 2018, 08:49 PM   #2
Patrick Bateman is offline Patrick Bateman  United States
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Kudos to Skydover, who clued me in on this find:

PRV wg45-50 and other 2" options - Technical/Modifications - The Klipsch Audio Community
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Old 3rd May 2018, 11:25 PM   #3
Soldermizer is offline Soldermizer  United States
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As always Patrick, a pleasure to see your exploits. I still wonder where you manage to store them all! Nice backyard, at least until somebody flicks a cigarette butt out their car window
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Old 3rd May 2018, 11:43 PM   #4
AudioLapDance is offline AudioLapDance  Canada
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I for one welcome our Plastic Unity overlords!

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Last edited by AudioLapDance; 3rd May 2018 at 11:46 PM.
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Old 4th May 2018, 03:51 PM   #5
Patrick Bateman is offline Patrick Bateman  United States
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If any of those Korean propaganda speakers show up on eBay, it looks like they'll work too! Size is just about right.
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Old 4th May 2018, 06:59 PM   #6
KaffiMann is offline KaffiMann  Norway
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Maybe get enough for a 5meter high Unity Array! And a stack of 15" woofers on each side of each array would be enough to match spl levels? So 2x5meters of tightly stacked 15" boxes per Unity Array.
I will start saving up for plane tickets if anyone is going that route!
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Old 4th May 2018, 07:23 PM   #7
Patrick Bateman is offline Patrick Bateman  United States
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As Bruce Edgar discovered, soft domes work nicely on horns. Based on a conversation I had with Andrew Jones, I believe that soft domes behave like ring radiators on horns. Basically at high frequency the apex of the dome is decoupled from the rest of the diaphragm. This leads to near ideal wave propagation on a horn.

This is the frequency response and distortion of a TangBand 29mm soft dome on the 2" horn. I made very little effort to mate it up properly, I just ratcheted the thing together with two clamps. So there's a gap of about 10mm on either side of the dome, which is what's causing that dip at 10khz.

This measurement includes EQ.

ETJQaVI.jpg
Here are my EQ settings.

aFZR56Y.jpg
Here's the polar response, from 0 to 44 degrees, with EQ. This is a ground plane measurement, performance in a room will be superior to this. Based on the measurement, it appears that my original 'hunch' was correct: the beamwidth of this horn is about sixty degrees.

All in all, not too shabby for $80 per side.
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Old 8th May 2018, 05:49 PM   #8
Patrick Bateman is offline Patrick Bateman  United States
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E6lYd61.jpg

Xs3f6SQ.jpg
I 3D printed a throat adapter, turning this 2" horn into a 1" horn. I matched the entrance angle to the exit angle of my BMS 4540ND.

1.jpg
Here's the polar response, measured groundplane

2.jpg
Here are my EQ settings

3.jpg
The results were promising, so I elevated the horn 1.5M off the ground, to see if that would smooth out the treble. It did, but introduced ripple in the midrange, due to lack of termination.

4.jpg
Here's the EQ settings
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Old 9th May 2018, 01:59 AM   #9
hollowboy is offline hollowboy  Australia
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Quote:
Originally Posted by Patrick Bateman View Post
But flip it over, YOWZA, that thing is deep. 30cm deep to be exact. That'll load your tweeter down to 283Hz and your mids down to about 340Hz.
Being narrow, it loses pattern control relatively high. I measured a jump at ~800Hz with mine, and it is nearly omni <500Hz.
http://www.diyaudio.com/forums/attac...-jbl-polar-jpg
That was the stock horn. I should re-measure this. With the extended mouth & big roundover*, the transition to omni should be lower and smoother.

Quote:
Originally Posted by Patrick Bateman View Post
So what's the downside? It sure isn't the price, it's only $40. And the build quality is better than Pyle.
- only one supplier, so ~double the price if you're not in the USA
- the walls aren't very strong; one of mine arrived cracked.
- the lip at the mouth is pointless: too small to have any acoustic effect, but prevents rear mounting (I had to cut & grind them flat).

Even so, it is still better value than pro equivalents I've considered (JBL 2386) or tried (Selenium HL 4750).

Quote:
Originally Posted by Patrick Bateman View Post
One lil' problem, this is a 2" horn, so it's going to need an adapter.
IMO, not a problem: they work well with a 2" alu driver. The top octave seems nearly as extended as from a 1" tweeter, and the bottom end is good to 500Hz. The latter seems like it'd be a huge win for a unity build. The low crossover would allow a mini version of Chris' MEH build.
A K-402-Based Full-Range Multiple-Entry Horn - Technical/Modifications - The Klipsch Audio Community

*post 39 shows ~current pix
paper cone open frame driver for front horn
I could construct a MEH with this: the ~100 litres behind the horn is enough to house a quad of 6" drivers and thereby get 93dB midbass sensitivity from humble Tympany drivers (which are cheap via Digikey). I could cross the whole mess to a sub at ~60Hz.

The narrow pattern and industrial appearance would be the major downsides.
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Old 9th May 2018, 02:10 AM   #10
Patrick Bateman is offline Patrick Bateman  United States
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Yep. If you ignore the flange, this horn measures 16" x 9.5. That means that it will start to go omni around 1080Hz.

(((16" x 9.5")^.5) / 13500))

For this project, I'm definitely considering the addition of a secondary flare, similar to what Danley / Waslo / Keele do.
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