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Hey guys...we need a little rallying here...

1M views 13K replies 544 participants last post by  dane10 
#1 ·

DOPE from HOPE Toe In.pdf 159k .pdf file

 

 

 

Setup of WG Speakers.pdf 206k .pdf file

 

 

 

Introducing...

logo design contributed by avs member omegaslast. thanks omega!


This thread has morphed from a rallying effort to encourage Parts Express to carry a waveguide into a full blown research and development project coordinated by Erich H to create a new one. On top of that, Erich H and contributors developed a couple new compression drivers, flat pack enclosures, and so much more. While I will provide some updates from time to time, the latest can always be seen by subscribing to this thread or visiting Erich's website:
http://www.diysoundgroup.com/

and the Official Project List in the forum.


The primary product that has emerged is the SEOS waveguide (Super Elliptical Oblate Spheroid describes the profile of the waveguide's curvature). The design objective was to provide good horizontal coverage for near constant sound anywhere in the room (controlled directivity for the audio wonks) and vertical coverage that would minimize floor and ceiling bounce, while minimizing the problems associated with traditional 'horns' (internal reflections and such).

 

If you don't know why controlled directivity waveguides are useful, don't worry, attached is a pdf that explains it. 

The design objective has been met. This waveguide provides the high dynamics and SPL capability of a compression driver without any of the "horn sound" that plagues other models.




Off axis performance is spectacular:



Several more pics here:
http://www.diysoundgroup.com/media/c...astic3_1_3.jpg
http://www.diysoundgroup.com/media/c...astic2_1_3.jpg
http://www.diysoundgroup.com/media/c...astic4_1_3.jpg


It is available in several options. The first and the premium option is high gloss fiberglass. The second is a poured concrete type product that costs about half as much. The third is the budget option, an injected molded plastic horn. All three will perform similarly.


The waveguide is available in 6" 8" 10" 12" 15" and 18", though not all models are available in all materials. Throat diameter is 1".


Here is some eye candy of the fiberglass models:








The fiberglass waveguides are available in most any custom color.



12" SEOS measured. DE250 driver, 2m distance, about 5' off the ground.

Horizontal patterns (measured in 7.5 degree steps, 0 to 90 degree range, curves unsmoothed):
http://www.avsforum.com/avs-vb/showthread.php?t=1369780




 

Member "java" is an early adopter and did a great job with his build.

 



Ground up build thread can be found here:

http://www.avsforum.com/t/1417294/seos12-2512-build

Member Brad Horstkotte's interpretation, SEOS 12/360 over a JBL 2226J woofer:



 

Build thread here: http://www.avsforum.com/t/1422024/seos-12-dna-360-jbl-2226-j-build

 

Erich has some flat packs coming together.  Here is an example of how simple they are to assemble:

 



More bwaslo progress...SEOS12 and Deltalite 2512 in a test box. Crossover was designed using measurements from the "lesser clone" driver. Here is an overlay of the 1m unsmoothed frequency response with that design using both the "lesser clone" and the DE250:
http://www.avsforum.com/avs-vb/showt...0#post21851410



The clone (and to a lesser extent, the "better clone") has a funny notch at 8.5kHz, but goes higher in frequency; DE250 doesn't have that notch. (Not visible in this design): The "lesser clone" doesn't go quite as low as the DE250 or the "better clone", but still very close.


Here are 90ish dB distortion sweeps. First the DE250:



Then the "Lesser Clone":


Not much to get excited about in either, both pretty clean. BTW, as a sweep, this is quite loud.




And another pic of the waveguide (plastic prototypes on the left and right, fiberglass in the center). The plastic SEOS 12" is being set up for injection molding, so the per-unit cost will be VERY affordable.






AVS member bwaslo has been running AE TD15M/SEOS 15/B&C DE250 and has amazing results in an active crossover setup. As of this update, he is working on a passive crossover network.




A 'prototype' build of his can be seen here: http://libinst.com/junk/TD15M%20SEOS15/photo2.jpg




AVS member AudioJosh has some pics of a build here:
http://www.avsforum.com/avs-vb/showt...8#post21711808




Here is a corner friendly concept: http://www.audiokinesis.com/images/p..._ak_prisma.jpg




As for one of the compression drivers in development, it is called the BA because it is so large, aka big ass, relative to the DE250.




Frequency response of the BA driver:
http://www.avsforum.com/avs-vb/showt...5#post21670315






There is also a DE250 clone in the works. Frequency response:

Black is DE250 on 15" SEOS, Red is clone driver on 15" SEOS.






Frequency response:






Also, a very low cost compression driver is in the works. Some early pics:






BWaslo's results of a first SEOS12 design. As built from a PCD design (using OmniMic measurements). The woofer is the (very soon to be announced) Dayton Audio "Designers' Series" 10 inch woofer. The cabinet is an old Advent Legacy II box.

http://www.avsforum.com/avs-vb/showp...postcount=3110






Malcolm, A SEOS12 Center channel (another one by bwaslo):
http://www.avsforum.com/avs-vb/showt...1#post21836431
The schematic for the Malcolm (v1) crossover
Malcolm Crossover Parts List from Parts Express








Full baffle options are coming soon. Prototype shown here:








Erich update:


Besides the 1 piece SEOS-10 baffle, most of the designs right now will revolve around the SEOS-12 and SEOS-15. But they're almost certainly going to be using the DE250 or other similar models. Even if someone comes up with a super high end model, it will likely be with a much more expensive woofer, but still use either the SEOS-12 or 15 and the nicer compression driver that showed a slightly better top end than the DE250.


Keep in mind, that every single option will be good. No one here wants to mess around with anything cheesy, it's just a waste of time right now. So when I say "low, mid, high", I'm talking about pricing, not necessarily sound quality.


It's also going to be hard to break things down into categories because all will be available as DIY kits, but some might eventually turn into completed speakers. But if they do, the boxes I'm thinking about will not be cheap. So you could DIY even the high end stuff, but the really high end will be considered completed boxes, but still the same "design". Hope I explained my plans okay.


Just to get things out in the open:


SEOS-8: There will be at least 2 designs. No 1 piece baffle or complete speaker in the works yet. You have to order the fiberglass or the poured version right now.


SEOS-10: There will be at least 3 designs. Low, mid, high costs. All can use the poured or fiberglass waveguide that you can order right now. Some will also fit the 1 piece baffle. You could use the 1 piece baffle for the cheaper model, it would be up to the person building it. Eventually (if an absolutely great design shows up) I *might* try to get an entire speaker made up for the 10.


SEOS-12: I'm guessing at least 5 designs minimum. With all the different woofer and compression driver combos, it could be even more. Obviously the plastic waveguide, the poured one, or the fiberglass model. I think this and the SEOS-10 will be the main focus. Because of the plastic option, some designs will be very well priced that anyone should be able to afford. Probably a few mid level designs, and maybe 2 higher end designs. If one of those higher end designs is incredible, then maybe a full speaker down the road.


SEOS-15: I know of at least 2 designs. But they're probably won't be a cheaper version here. You can order the poured model or the fiberglass model. I don't think there will be a 1 piece baffle. I doubt a completed speaker like the other sizes would be available.....in the cabinet design I'd like to see. It would just be quite expensive.


SEOS-18: I know at least 2 designs here, possibly 3. Same info as the SEOS-15.





*********************

It can't really be put into words how much work and how much money Erich has invested in this project. He financed the whole thing and invested countless hours coordinating with people around the globe. So when you build a SEOS project, at least post your build and/or drop Erich a thank you note. Also, spread the DIYSoundGroup word around...


As with all projects, this one is not the work of one person.


SEOS is a trademark. The name and logo are copyright (c) 2011-2012. All rights reserved. For commercial use, contact Erich H.

This project is dedicated to the memory of our friend who went by the callsign Zilch.

More data, less wank.


Z's avatar is itself a dedication to the memory of James B. Lansing.






The original post:


As many of you know, Zilch & Co. have created some great crossovers for a horn loaded main that uses the QSC 152i horn. It appears that QSC has cut us off from direct buys of this horn, but Parts Express, as a QSC distributor, may be able to supply our fellow forum members if we can rally enough interest.


Folks, I am asking that you shoot a quick email to Parts Express and let them know how much we appreciate their support of our community and that we would appreciate it if they could continue to provide the QSC 152i horn for DIY builds.


Each horn sale from them typically results in an additional sale of a woofer, a compression driver, and many crossover components. QSC gets the benefit of proving their good products among a very vociferous group of folks (lots of free online marketing) P.E. has been a long time friend around here so don't go negative however this one turns out.


The email addresses are here:
http://www.parts-express.com/contact.cfm


Thanks.




 
 

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#28 ·

Quote:
Originally Posted by Erich H /forum/post/19518714


Then I'll just wait until you hear something. If they don't carry the part, then I'll get with Zilch and see if he thinks the QSC could be modified to be even better and we'll go from there.


If you hear anything, let us know.


Eric, do you have the QSC? I think you still should build a baffle no matter what happens. The only modification I think someone was cutting out a bottom curve on the waveguide so that the woofer / CD CTC is closer.


A one part baffle makes everything look professional and clean.
 
#29 ·
Yeh, I've got 2 of the QSC's. One thing I noticed on both of mine was that the inside throat isn't 100% smooth. I know they're probably all like that. It's because of the way they molded the bracing for the compression driver. I mean it's not rough or anything, but you can feel some very slight humps in the plastic.


I'm going to do the entire baffles, but I'm leaning towards making them completely out of wood first. Just waiting on some parts for a CNC type setup. Hoping to be going on this just after Thanksgiving.
 
#33 ·
Thank you Craig!


It's good to know they are aware of this and working on it for us....
 
#35 ·
"Thank you Craig!"


+1


"a asymmetric oblate spheroid 90x60 about 17" wide."


a little narrower in the vertical, perhaps a 90x50, and with nice large smooth transitions from the horn wall to the baffle might be a little better.


this guy did a ton of research and built some really nice horns:
http://www.audioheritage.org/vbullet...s-in-solid-Oak


he might be worth contacting for ideas in order to see what he might choose to do given no limits.


here is a pic of a setup that uses 15"s and a nice big assymetric horn. i forget whose work that is.

 
#36 ·
Quote:
Originally Posted by coctostan
If someone wanted to get crazy, they could build a asymmetric oblate spheroid 90x60 about 17" wide. I'd buy a bunch of those. It shouldn't be too hard to model with some math.
I definitely would too!
 
#37 ·
LTD, that pic is along the lines of what I'm thinking although I prefer a baffle mounted version.


Directly copying the QSC is a little questionable ethically IMO. At least if it is done for more than your own use. I think it would be more appropriate to do something similar or improved. Something similar to the 152 horn but with more width would be great, but I think a asymmetric OS WG would be the best.


This is what I'm thinking:


1. Develop the mathematical model to create a graphic representation of the profile.

2. Take that model and create an actual 3D model with the appropriate material thickness, baffle mounting area, and driver mounting area

3. Send it to a 3D printing/rapid prototyping shop for a 1-off

4. Make some casting molds using the 1-off

5. Cast horns using a rigid urethane plastic


Doable?
 
#39 ·
Yes, doable, but the transition between a round compression driver exit and elliptical flare is critical; that's where the action is, and I think it's also going to vary depending upon the driver exit angle, as well. Doing a two-piece design, throat adapter plus flare, may comprise the most rational course, at least at the prototype stage, until the variable detail is defined....
 
#41 ·

Quote:
Originally Posted by ZilchLab /forum/post/19540162


Yes, doable, but the transition between a round compression driver exit and elliptical flare is critical; that's where the action is, and I think it's also going to vary depending upon the driver exit angle, as well. Doing a two-piece design, throat adapter plus flare, may comprise the most rational course, at least at the prototype stage, until the variable detail is defined....

In simple terms this is what I'm thinking:


You determine a specific ellipse shape that is the mouth of the horn. At its tallest and widest extents it is a 90x60 (or whatever flavor you want) horn.


The profile at the widest extent can be calculated as a 90 deg flare at a certain radius plugged into the OS profile formula.


The profile at the tallest extent is similar but with a 60 deg flare and smaller radius.


For all points between the tallest and widest, you can calculate the flare and radius to be used. It will terminate to a circle at the throat because the same throat diameter value is always used.


I could easily be mistaken in my assessment as I haven't tested it thoroughly. Please point out where it is more complex.


Edit: Forgot to address driver exit angle. I agree, each OS profile, in order to be optimal is setup for a specific CD exit angle. IMO, the DE250 is the best exit to go with because I believe it is documented, the driver is readily available, moderately priced and well accepted as a top notch CD.
 
#42 ·

Quote:
Edit: Forgot to address driver exit angle. I agree, each OS profile, in order to be optimal is setup for a specific CD exit angle. IMO, the DE250 is the best exit to go with because I believe it is documented, the driver is readily available, moderately priced and well accepted as a top notch CD.

Someone (mabye edlafontaine on PE) posted a decent list of CDs with exit angles. I will have to look. Its either on PE or DIYaudio.com
 
#43 ·

Quote:
Originally Posted by penngray /forum/post/19541138


Someone (mabye edlafontaine on PE) posted a decent list of CDs with exit angles. I will have to look. Its either on PE or DIYaudio.com

I believe this is what you're looking for:


Here are the exit angles I've collected, but can't vouch for the accuracy. I believe all are overall angles (/2 per side).


18sound:

NSD1095N, ND1090 = 27°

NSD1480N = 10°



B&C


1"

DE250 14.6°

DE10 7.7°

DE12 24°

DE400TN 20.7°

DE400 31°

DE500 17°

DE200 9.9°


2"

DE85TN 34.5°

DE750TN 22°

DE950TN 17°


BEYMA:


CP750Nd - 24º

CP850Nd - 7º

CP755Nd - 12º60'

SMC65Nd - 15º

CP385Nd - 16º30'

SMC225Nd - 13º1'



jbl 2450 10+°

radian 950 20+°
 
#44 ·
Quote:
Originally Posted by coctostan
LTD, that pic is along the lines of what I'm thinking although I prefer a baffle mounted version.


Directly copying the QSC is a little questionable ethically IMO. At least if it is done for more than your own use. I think it would be more appropriate to do something similar or improved. Something similar to the 152 horn but with more width would be great, but I think a asymmetric OS WG would be the best.


This is what I'm thinking:


1. Develop the mathematical model to create a graphic representation of the profile.

2. Take that model and create an actual 3D model with the appropriate material thickness, baffle mounting area, and driver mounting area

3. Send it to a 3D printing/rapid prototyping shop for a 1-off

4. Make some casting molds using the 1-off

5. Cast horns using a rigid urethane plastic


Doable?
Here's a spreadsheet for an elliptical OS to get you started with the math. As usual with my (in)famous spreadsheets, it works but it's butt ugly.



About matching the CD exit angle to the horn, I don't think it's a big deal. You can build the horn for a 0 degree exit angle and a few strokes with a piece of sandpaper wrapped around your finger will smooth the transition well enough for guvment work. Even Earl uses modeling clay at the transition to smooth things out.




 

Elliptical Geddes.zip 52.1787109375k . file
 

Attachments

#45 ·
90x50 hehe...+1. quick and dirty spreadsheets that work...+1.


given how important the radius is in the throat transition, might it be better to have more resolution on the "slices" in that region. then there is the transition to the baffle. perhaps a large radius roundover would be better (may or may not be needed, at first i thought yes, but so many successful designs that lack it)? nice work d.
 
#46 ·
Yeah, that was just an experiment in getting the math right when Earl was saying it was so hard.
You'd need much thinner slices for a CNC machine and you'd need to deal with the round-over at the mouth too. But it's a start....
 
#48 ·

Quote:
Originally Posted by LBDiver /forum/post/19541365


I believe this is what you're looking for:


Here are the exit angles I've collected, but can't vouch for the accuracy. I believe all are overall angles (/2 per side).


18sound:

NSD1095N, ND1090 = 27°

NSD1480N = 10°



B&C


1"

DE250 14.6°

DE10 7.7°

DE12 24°

DE400TN 20.7°

DE400 31°

DE500 17°

DE200 9.9°


2"

DE85TN 34.5°

DE750TN 22°

DE950TN 17°


BEYMA:


CP750Nd - 24º

CP850Nd - 7º

CP755Nd - 12º60'

SMC65Nd - 15º

CP385Nd - 16º30'

SMC225Nd - 13º1'



jbl 2450 10+°

radian 950 20+°

Thanks!


There was a discussion about the DE250 angle being different but I couldnt find out the answer.


I should try to measure the angles of my CDs, I have to figure out how to measure them first some have screens over the mouth.
 
#49 ·
Great work Dennis. I'm going to try to implement a Sketchup script that will give us a 3D model for elliptical horns. I might try to implement it with the option of superellipses as well. I'm new to Ruby scripts so don't expect something right away.


Concerning driver exit angles, the two most popular CDs, the DE250 and CP385ND within 1.5deg of each other. Manufacturing margin of error would likely be greater than that. IMO, we could target 15deg and it will perform admirably.


I just don't see multiple molds or plugs being feasible, let along multiple production runs for different drivers. These won't be $15 horns either when you account for tooling cost so you might as well splurge on nice CDs. This isn't frugal DIY, IMO.


I think the project might be feasible.
 
#51 ·
what is the advantage of the CP385ND over the CP380M?


frequency response, distortion, and price look better on the latter.


385

$249



380

$189



i just linked them in from us speaker. i didn't make the 380 image larger.
 
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