Our secondary horns have a 3D printed frame with a cam-lock, slips on in 5s. We are making a simple tension line setup to keep the top from spinning in wind. Lol.
Hi all! I'm starting the build process on the secondary horns and got to wondering, is there any benefit to building them bigger than the original plans? I have room to spare so if there is a bump in efficiency or improvement in pattern control I'd be willing to scale them up within reason.
@MrSpeakers Do you have any pictures of your cam lock system? I'm still figuring out how I want to hold them on.
@MrSpeakers Do you have any pictures of your cam lock system? I'm still figuring out how I want to hold them on.
A larger secondary horn will extend pattern control to a lower frequency and provide more forward gain.
We thought about that but it does want to spin on the pole as-is so an anchor system would probably be essential. 2 ratchet straps or wire cables should suffice...
Extra gain to lower frequencies would help because it's almost always the 10" that limits our peak SPL from the system.
That cam lock system looks awesome!
I use the K&M ring lock poles with a M20 threaded mount on the subs right now to keep them from turning and they work great. Hopefully that remains true with the secondary horn attached. I used to ratchet them in place but the way I had it set up forced me to use the same angle each time and I couldn't turn them to toe in or out.
Just want to chime in with the others and say excellent work. Did you get your set complete? Would you be open to sharing your files for the "mudwork" inserts, or the set at large?
Thanks to Art and everyone for sharing their knowledge and experiences on the builds. Have 2 Keystones and cant wait to start on these as a compliment.
Hi Art,
First time poster here, but I've been studying this thread for months now and feel ready to tackle this build together with my crew.
We are not experienced woodworkers, but one member of our crew is really experienced in working with fiberglass, having been into the hobby of building RC planes for a long time. Our thinking is that we could make the inner horn out of fiberglass, while keeping the outside shell made of BB. Possibly, some wooden panels would also be needed in the inner horn to mount the two 10". Do you think fiberglass could work (acoustically), provided that it's thick enough/braced enough to avoid audible vibrations?
Furthermore, once we have a mold, we could easily produce as many "inner horns" as we want. Provided that our build is successful and measures up to your standards, would you be interested in licensing the design so that we can sell the "inner horns" to other DIYers?
If you think this is worthy of exploring, I'd love to discuss it further via email.
First time poster here, but I've been studying this thread for months now and feel ready to tackle this build together with my crew.
We are not experienced woodworkers, but one member of our crew is really experienced in working with fiberglass, having been into the hobby of building RC planes for a long time. Our thinking is that we could make the inner horn out of fiberglass, while keeping the outside shell made of BB. Possibly, some wooden panels would also be needed in the inner horn to mount the two 10". Do you think fiberglass could work (acoustically), provided that it's thick enough/braced enough to avoid audible vibrations?
Furthermore, once we have a mold, we could easily produce as many "inner horns" as we want. Provided that our build is successful and measures up to your standards, would you be interested in licensing the design so that we can sell the "inner horns" to other DIYers?
If you think this is worthy of exploring, I'd love to discuss it further via email.
and labor would probably exceed building it from plywood even after creating a mold by a good margin.
Adding all the machining needed on the speaker side of the horn would require another set of molds for the baffle parts which could then be laminated to the carcass, along with Balsa wood or foam core for stiffness.
I’m getting itchy just remembering all the details of fiberglass construction, even though I haven’t done any since 1979..
If making a mold, there would be no reason to use straight sections, a profile like this, as simulated by Mabat would improve polar response:
https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7132867
Speaking of improvements, going three-way would be another ;^)
At any rate, I’d be glad to collect license fees, though at the price you would have to charge to make a profit (and pay yourself more than the $7.25 minimum wage) after shipping, don’t think there would be much of a market for a DIY kit of this nature.
Art
Thanks for your thorough response Art!
The viability of selling kits would be assessed once we have completed our two first cabinets and we have full information about labor, actual material costs, etc. Our first and primary objective is to complete our own complete system, which will be a feat in itself 🙂
While making the inner horn in fiberglass will certainly take more work than making it in wood, we have several reasons to consider it for our own build:
Of course, it will all need to be prototyped and properly measured so that we can be sure that our construction methods are not messing with the properties of the design.
As far as implementing improvements to the design:
The viability of selling kits would be assessed once we have completed our two first cabinets and we have full information about labor, actual material costs, etc. Our first and primary objective is to complete our own complete system, which will be a feat in itself 🙂
While making the inner horn in fiberglass will certainly take more work than making it in wood, we have several reasons to consider it for our own build:
- The cost of BB in Spain, where I live, is through the roof (+150eur for a sheet of questionable quality).
- We already have most of the materials and tools needed for fiberglass shaping and finishing, while we own very little woodworking tools.
- One of us already has the necessary skills to tackle this build in fiberglass.
- We could (try to) integrate the round to square CD transition at the throat in the same piece as the inner horn, removing the need for machining or hand-forming the throat adaptor plate.
Of course, it will all need to be prototyped and properly measured so that we can be sure that our construction methods are not messing with the properties of the design.
As far as implementing improvements to the design:
- A later upgrade to a DCX 464 coaxial compression driver is planned but is not a possibility in the first iteration of the system due to cost. We'll go with the original driver recommendations until we can afford the upgrade.
- The possibility of making the horn walls follow an OS-SE curvature instead of making them straight is very interesting, as it would both improve polar response and rigidity of the fiberglass construction. My question is: ¿Would it mess with the design of the injection ports and the bass reflex ports and thus require a redesign of these parts? That might be more than we can chew at the moment, but I'm willing to look into it.
I would go 3 way rather than using the DCX 464 or other coaxial driver, it has been discussed earlier in this thread and would give more output.
1) As far as improvement going three-way, using cone mids rather than a coaxial compression driver is what I had in mind, as they are more cost-effective in terms of SPL output and sound quality.
2) The OS-SE curvature is fairly little, it would hardly affect Fb.
All buttoned up. First impressions are fantasmo. Hoping to haul them somewhere that I can turn them up and do some measurement/EQ work. I'm admittedly new to this. Anybody with SyntripPs using DE90TN have measurements that I can compare with?
DSP is a DriveRackPA2
Crown XLS1000 driving the highs (DE90TN)
NX3000 driving mids (10CL51)
NX3000 bridged driving the single Keystone (18tbw100-4)
DSP is a DriveRackPA2
Crown XLS1000 driving the highs (DE90TN)
NX3000 driving mids (10CL51)
NX3000 bridged driving the single Keystone (18tbw100-4)
You didn't mention any insulation in the SynTripP, if you didn't follow the assembly instructions in post #61, you should before bothering to tune them. Post #9 had initial DRPA DSP settings.
IIRC, the DriveRackPA2 High output polarity may be inverted from the Mid, something to check for, especially if you find a hole in the mid/high crossover region.
No photos, but there is egg crate type foam on the back panels, save for behind the compression driver (no room) and the edges where the plastic mounting pieces are at. I wasn't sure of what the instructions meant by the triangle areas. Hopefully this will suffice - I think I've read that the insulation helps with a few resonances?
Will check on the PA2 high output polarity - thanks for the heads up!
Do you have a suggestion for where to cross these with the Keystone?
Will check on the PA2 high output polarity - thanks for the heads up!
Do you have a suggestion for where to cross these with the Keystone?
Yes, the insulation damps some resonances and standing waves in the cabinet interior. The "triangle areas" are the upper and lower corners, the bottom pair get covered, upper wasn't in mine, but won't hurt. Keep the port entry areas clear.
Anywhere from around 75Hz to 125Hz will work well between the Keystone/ SynTripP, shift up or down from 100Hz depending on what runs out of headroom first.
Art
Hey Art/gang- small point of clarification while I'm building my drawings: trying to determine whether the horn structure should sit flush with the outer "box," or be inset to leave room for a grill frame. Studying build pics, I think I've seen it both ways? If inset, is there a specific distance? Many thanks.
