I'd like to see more info on these but can't seem to find in here. Have you posted photos and info somewhere?
Ha! I've been doing the same lately. When I opted to sell a 3D printed waveguide, it occurred to me that it's perfectly legal to do as long as it's a Unity horn.
I'm thinking about having a crack at a 3-way unity, what do you guys think about the new Alpha-2 8s? Would be able to locate the bandpass holes very close to the horn mouth, plus it looks like you could probably mount them flat without cutting recess for the surround etc, and there is a front mount gasket!
Eminence Alpha 2-8 speaker. The Eminence Alpha 2-8 is a 2" 8 ohm fullrange speaker. Alpha-2-8 is a 20 watt RMS 2" full range speaker.
LF drivers I have already are the B&C 10nw64
HF drivers I have already are the PRV Audio D230Ti-Nd-B (on sale!)
One thing I can't quite get my head around is how much area do you need to allow for the LF slots? the entry point needs to be as close as practical to the horn mouth, inside the 1/4 wave of the lowest Freq. you plan on playing (so, 80Hz?) can someone kindly explain or point me in the right direction for the LF slot explanation. Cheers!
Eminence Alpha 2-8 speaker. The Eminence Alpha 2-8 is a 2" 8 ohm fullrange speaker. Alpha-2-8 is a 20 watt RMS 2" full range speaker.
LF drivers I have already are the B&C 10nw64
HF drivers I have already are the PRV Audio D230Ti-Nd-B (on sale!)
One thing I can't quite get my head around is how much area do you need to allow for the LF slots? the entry point needs to be as close as practical to the horn mouth, inside the 1/4 wave of the lowest Freq. you plan on playing (so, 80Hz?) can someone kindly explain or point me in the right direction for the LF slot explanation. Cheers!
It doesn't look bad.
The Gento midrange that Bill Waslo used in his first Unity horn works pretty darn well. It's a bit of a hassle to seal up the basket and wire the speaker, and that's the main reason why I have fifty of them but haven't actually used 'em lol.
The Gento costs $2 from Speaker Addict on eBay, so quite a discount over the Eminence
I have a bunch of the Tymphany TC6 and they work well too. I've used them a couple times. I can't really distinguish any difference from the Gento but YMMV
For my money, the easiest route is to simply use a single Misco or Celestion mid. Both of those drivers will deliver as much output as four 2" drivers, or more. I continue to use 2" mids for other reasons. In particularly, I do a lot of car audio stuff and the depth of the driver counts for a lot. (The Celestion is almost 4" deep. It's almost as deep as it's wide.)
The Gento midrange that Bill Waslo used in his first Unity horn works pretty darn well. It's a bit of a hassle to seal up the basket and wire the speaker, and that's the main reason why I have fifty of them but haven't actually used 'em lol.
The Gento costs $2 from Speaker Addict on eBay, so quite a discount over the Eminence
I have a bunch of the Tymphany TC6 and they work well too. I've used them a couple times. I can't really distinguish any difference from the Gento but YMMV
For my money, the easiest route is to simply use a single Misco or Celestion mid. Both of those drivers will deliver as much output as four 2" drivers, or more. I continue to use 2" mids for other reasons. In particularly, I do a lot of car audio stuff and the depth of the driver counts for a lot. (The Celestion is almost 4" deep. It's almost as deep as it's wide.)
There are many successful designs using 4" drivers. Why use those expensive, low sensitivity drivers unless you have to. And you might have to because of the expansion rate if you are planning a 90x60 horn but at 90x45 and smaller there are successful DIY designs done with 4" drivers.
As to the LF slots, its 1/4 wavelength at the highest frequency the driver plays, not the lowest. Some use a slot area that results in a 10:1 compression ratio; that is conservative. You can justify smaller slots by doing an HR simulation and looking at the peak particle velocity. You need to do that HR simulation to see where your mids become excursion limited and need to hand off to the woofers.
So happy to finally be starting my project in the coming months. I have the Celestion closed back mids on order and will be using the Beyma TPL200 as the tweeter. The parts wont get here for another few months but just so happy to see the light finally. Been years I have talked about this project.
I have look at the Synergy calc, nice software, make it more easy when I have look through it. However, when using midranges with closed back I need to do lrc
small and vrc a large number, I did that and see a big circle and no horn, this is because of the uge vrc, but can I use the setup that way>, little confusion.
I go to use the visaton frs8-m 30 watts version, do close the back with peace of pipe and cover and refit the connections.
regards
small and vrc a large number, I did that and see a big circle and no horn, this is because of the uge vrc, but can I use the setup that way>, little confusion.
I go to use the visaton frs8-m 30 watts version, do close the back with peace of pipe and cover and refit the connections.
regards
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If you've never built a Unity horn, save yourself a lot of frustration and use what Danley uses: the Misco sealed back 5" or the Celestion sealed back 4".
They work, they're easy to work with, it's a no brainer.
If you look at Danley's big designs, they frequently use multiple compression drivers at the throat, or a coaxial compression driver.
I believe part of the reason that he does this is because you have to drop the crossover point really REALLY low as you make the beamwidth wider.
IE, an SH50 has fifty degrees of beamwidth, that's close to the max you're going to get out of a 1" compression driver. Danley's Jericho J2-96 is 90x60, an average beamwidth of 75 degrees, but he had to use TWELVE compression drivers to make it work. Basically they're in a line, and each compression driver provides five degrees of beamwidth. At low frequency, they act like a single unit, and allow for a crossover point that's over an octave lower. Danley had to use a pile of compression drivers because the wider the beamwidth, the harder it is on a loudspeaker. The Danley SH25, with just twenty five degrees of bandwidth, is about as loud as a Jericho horn... as long as you're "in the beam."
I like going the OPPOSITE direction: instead of using additional compression drivers, I like using ultra small midranges. They allow you to widen the beamwidth, while moving the midranges closer to the throat.
Danley doesn't have this luxury; if he used 2" midranges his maximum output would drop like a rock. But I don't care if I can hit 130dB, I'm just trying to eliminate the 'hole' that appears when the mids are too far from the tweeter.
https://www.parts-express.com/pedocs/specs/264-1626--peerless-tc5fc07-04-spec-sheet.pdf
This new driver from Peerless is an interesting example of what I'm talking about. It's only two inches in diameter, but it has the right Thiele Small to be used in a Unity horn. And because it's so darn tiny, you can widen the beamwidth and bring the midranges closer to the compression driver.
Last summer I did a Unity horn with a 90x60 waveguide and 5" midranges, and found that the geometry made it impossible. Basically I couldn't get the midranges close enough to the compression driver. Worked on it for two weeks and had to throw the whole thing in the trash.
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Ha! I did the same thing last fall but only in Sketchup and HornResp but I could tell from that it wouldn't work, even with 3" drivers, IIRC. I changed the 90x60 to 60x60 and it was fine, still on paper. But thanks for the post on these drivers. Maybe 8 of them on each 90x60 would do the trick.
Was that the QSC waveguide?
I've wanted to tinker with Unity horns for a long time. I was just thinking of the QSC along with the Celestion 4" midrange. Any obvious issue there?
But then I wonder about "Unitizing" a relatively small waveguide such as the QSC or SEOS15. It seems the lowest frequency these hold the horizontal pattern is just about the lowest you want to play a good compression driver like a B&C DE250 or BMS 4550. For domestic use, what would the addition of bandpass midrange drivers really do? You can't really play the waveguide lower. Perhaps distortion? Then again, the better 1.75" diaphragms CD's can play loud enough to the WG's lowest frequency with IMO acceptable levels of distortion. Am I missing something?
see Bwaslo's SmallSyns thread about synergizing a SEOS15
Yes these waveguides were designed for use with a midwoofer below and so hold horizontal pattern control down to only 1 khz or so but the benefits of synergization are orthogonal to the benefits of controlled directivity, which increase with waveguide size.
Synergizing eliminates the lobing problems and center to center distance concerns associated with conventional wavequide designs and gives a perfect midrange-tweeter directivity match because they have the same directivity down to where pattern control is lost,
A synergy bandpass mid includes an acoustic lowpass filter that attenuates midrange distortion products.
The near full range point source maintains its on-axis frequency response over a wide range of listening heights much better than does a conventional multi-way speaker. For the same reason, the reverberant sound field it produces tends to be smoother and flatter.
For all these reasons, the synergy simply sounds better. Yes a larger horn would be even better but even a small waveguide and tweeter used in a synergy will sound better than the same waveguide and tweeter used in a conventional 2 or 3 way waveguide speaker
Yes these waveguides were designed for use with a midwoofer below and so hold horizontal pattern control down to only 1 khz or so but the benefits of synergization are orthogonal to the benefits of controlled directivity, which increase with waveguide size.
Synergizing eliminates the lobing problems and center to center distance concerns associated with conventional wavequide designs and gives a perfect midrange-tweeter directivity match because they have the same directivity down to where pattern control is lost,
A synergy bandpass mid includes an acoustic lowpass filter that attenuates midrange distortion products.
The near full range point source maintains its on-axis frequency response over a wide range of listening heights much better than does a conventional multi-way speaker. For the same reason, the reverberant sound field it produces tends to be smoother and flatter.
For all these reasons, the synergy simply sounds better. Yes a larger horn would be even better but even a small waveguide and tweeter used in a synergy will sound better than the same waveguide and tweeter used in a conventional 2 or 3 way waveguide speaker