Hey guys...we need a little rallying here... - Page 12

Was there a measurable difference in response, if so by how much, link?

As would I, just don't assume others have these machine tools as well.

I have not used a screw-on CD before, can you damage the CD by over tightening=compression at the throat, making the rear mating between the physical end of the WG and the CD thread shoulder critical to avoid crush? Otherwise, I would think a 1/16th off +/- via file, sander, something shouldn't be too much for the average consumer.

The threaded "snoot" is usually part of the casting in these little guys, i.e., one-piece. That could be turned down a bit more, but I don't think anybody fancies the prospect of secondary machining compression drivers, either. I doubt Celestion would provide a custom variant except on large OEM orders, maybe....

Sorry about that, back on topic.

The 15" EOS looks to be the choice of many, including the "either" votes.

How many votes are we looking for before we move forward with a specific design?

Which CD do you prefer to have this WG optimally matched to?

Who is willing to send money directly, or into an online escrow account to move this project to the prototyping phase?

What are your guys thoughts on having the flange and critical throat machined from aluminum and then cast into the horn? It may be possible to get away with a simple male mold and fiberglass/resin construction, may be a cheaper alternative for the first prototype or low #'s manufacturing.

What is the preferred material of construction and color for those interested?

Who would prefer to have an elliptical flange vs a rectangular? If we are going to pay to have a mold made and units run-off. Getting 20 ellipse templates cut out of 1/4" hardboard for use with a router guide bushing will be cheap in comparison.

Jzagaja, or somebody else with the capability, are you willing to complete the CAD/CAM model with the necessary throat and CD flange, as well as the horn screw flange?

What about adding any stiffening ribs at the CD flange to horn transition, also any stiffening ribs along the back of the horn wall for overall rigidity?




My answers:

CD- Whichever that is </=$200 and gives the most even FR and low frequency extension to achieve 1000hz XO.

Money- Will put $75 in escrow contingent on a spec prototype being completed.

Material- Aluminum mounting plate and throat with anything strong enough and a smooth surface finish for the rest.

Color- Black

Flange shape- Elliptical with router template.

Once we agree on EOS profile I expect a list:

Customer....Driver or holes sketch ....Color......alu or mdf flange (mounting plate)

I assume 25mm throat for fine tuning, white color, mdf flange, 100mm diameter without holes. Ribs aren't necessary - this is for homes use. Bitumen layer can be sprayed or brushed afterwards (not necessary).

The last batch of ENG-190s that I got directly from DDS were excellent. Beautiful cosmetically, thick but not too thick fiberglass. I still have to grind the back of the flange flat and do some touchup here and there. Occasionally there are thin spider-thread cracks in the surface gelcoat, but they're easy to hide with a correspondingly thin sharpie. One slight issue was that the custom 8-hole-flange configuration I got did not have the 8 holes perfectly equi-distanant from one another, but that was not hard to work around. Unfortunately they don't photograph very well, or I'd post a link.

Now one of the problems you guys would have is, we don't know the generation of the stock that vendors have on hand. You can ask 'em, and make sure you have return privileges, or maybe even organize a group buy.

The DDS waveguide has a larger diameter "lip" than the Geddes profile. This means the on-axis dip is shallower, but also that pattern control degrades at a bit higher frequency.


I grinded down the backside of the first few Pyle horns, and then I forgot to do so on a pair and took 'em to an audio show and nobody (including me) heard anything amiss. When I got home I did a blind test and the difference was apparently inaudible. So now I don't worry about it. I end up doing some whittling on most of the horns in the throat area, as there's a little bit asymmetry in the mold. Also every now and then I get a horn with the threaded hole clearly off-center by a significant margin, and those get discarded because they'd be too hard to fix.

It looks like a general design is pretty much agreed upon. Not sure how many more specifics will need to be ironed out. But it might be time for step 2.


I didn't think this was a group buy, but maybe it went that way. I thought we were going to agree on a design and then get a prototype made up? A group buy will only help a few people in a short time window, we need to figure out a longer solution for this problem and for more people. We need a lot, not just a few. No reason for designing anything if weren't talking about 10-20 people.

Jzagaja mentioned to me that it costs a LOT of money for shipping unless we do entire pallets, and even then, it gets quite expensive. Like $800 for just the pallet to be shipped to a port! I need to discuss this more with him though.

I told Penngray that it might make sense to see if jzagaja could make us a prototype if we agreed on what's needed. He knows how to model them and create the 3D file and he does great work. If he can't make us a prototype, then maybe I can pay him to do a very nice 3D file so that we can find someone here to make the prototype for testing. Making up a one off prototype would cost much more than his normal run of waveguides I'm sure, but it could be better than a 3D printer, or a milled prototype. In the end, it would likely about the same price.

Erich,

I was under the impression you were going to have this prototyped stateside, no? Are you not free to use the file provided? The conundrum is do you have a quick and dirty mold made from wood/foam so that a cheap and easy prototype can be made for testing, or do you go full gusto expecting it to perform as designed and make everybody happy.

Regarding it being a group buy or a marketed product, at this time I believe it should be looked at as a "group effort". Unless you're willing to risk the cash on a failed or potentially knocked-off product I figure it would be best to start small, and keep initial costs as low as possible. Counter to which would be paying large sums shipping product across the Atlantic. In addition if you're really thinking big then it should ultimately be infection molded. `

Ultimately some base number of potential customers has to be realized in order to price the product in the short term since the majority of the cost is going to be R&D/Protoyping.

Yes, the costs of making a prototype and getting it made up were discussed. The answers to your first paragraph were posted in the thread a few days ago, might have been last week, not sure. Injection molding was an option after that, but obviously it's expensive, so other ways need to be explored.

No design is going to make everyone happy, as stated earlier, this is like politics and religion. There won't be a definite answer for everyone, but that shouldn't stop us. Lots of people like Polk and hate Klipsch, and vice versa, but they both keep making speakers.

I have to send the file to someone to have it looked at, I'm not sure if it's what he needs or not right now. When I called him this week, he said his brother was just taken to the hospital but he would call me back in a couple days. Obviously I didn't want to push it on him at that point.

I'd be in for whatever size, but I'd pay more for a larger horn than a smaller horn. I'm probably unique in that regard, but if I'm going to spend a decent chunk of change I'd like it to be closer to Porsche than Toyota if you catch my drift...even if it is less practical.

I'd say that for a smaller horn like the 15" EOS I wouldn't want to pay more than $100ea. I'd be more interested in something 18-20" myself to get pattern control down to 800-900hz as I've stated before. That would be worth maybe up to $200ea to me.

I do like the idea of buying a plug from someone and then creating molds from it in the US, if the source is fine with that. I think a poured urethane into a silicone mold would be fine. Injection molding is well beyond the scope of this project, IMO...unless Parts Express was interested in taking the lead. Has anybody thought about floating it by them as a Dayton product?

Just to be sure we're on the same page here, when we say "15 diameter," what we mean is 15" WIDTH; it's an ellipse, and the design in-hand has a 10" vertical height with integral mouth roundover generating a 90° x 45° pattern.

My perception is that Erich H will be making a prototype of that for measurement and performance testing prior to committing to a small-scale production mold.

I doubt this would have any traction with Dayton without a proven design and demand....

Yeah I read the previous, hence my questions when the discussion turned to paying $$$ to ship a pallet across the Atlantic, probably just a mix-up. It seems I got lost between "we need a lot" and "10-20" Too me "a lot" is minimum 100 people, and since I assume most people will want a pair, were talking 200+ units. This quickly turns a $5,000 injection mold into a $25 or lower fixed cost per horn which is very reasonable, ultimately making these $60-75/piece items. Hence why I was trying to clarify the situation, ultimate consumer expectation's.

What seems most reasonable to me is to have someone with a quality wood CNC (not ShopBot or AXYZ) with a high Z axis (5"+) and have them create a 2 or 3 piece male mold with registration pin holes and then spin up a aluminum flange on a lathe so we can get a working prototype. If you were provided with a STEP file it shouldn't be a problem, it's a common 3D file format.

By "making people happy" I did not mean everybody, rather that the prototype performs to a high enough standard that the parties interested are willing to pay money to have a copy made for themselves. Bottom line scenario, I don't want to see you or anybody else left hanging with a large outlay for something that is abandoned/goes nowhere.

What waveguide do you want?

1. Penngray - 15" EOS
2. LTD02 - 15" EOS
3. 3AMRecords - 15" EOS
4. Noah - 12" EOS (assuming it holds pattern control down to ~1.2 kHz or less)
5. Zilch - Minimum 12" EOS (+cab roundover) assuming there's minimal on-axis notch
6. Erich H - either
7. JoshK (AudioJosh) - either with preference for 15" EOS
8. Bwaslo - 15" EOS, but either ok. 1" exit CD.
9. DS-21 - depending on cost (too rich for my blood and the incentive to swap out the 12" Tannoy DC's gets markedly lower), 15" EOS, 1" exit and throat-matched to a known-good CD (don't care which: B&C, BMS, Beyma, etc.)
10. P Monger - 15" EOS
11. LBDiver - Whichever will lead to it actually being built (current 15"-EOS w/ roundover looks good)

I'm potentially interested in a pair of these, but it depends on what the group decision comes out being as well as price as shipping could easily be more than the WG's. 15" EOS would be OK.

Well, I don't have the same level of interest as most others do so far as I'm confident the current projects will be long term keepers. My interest is more for experimentation.

Okay. In that case:

[quote=A9X-308;19595889]What waveguide do you want?

1. Penngray - 15" EOS
2. LTD02 - 15" EOS
3. 3AMRecords - 15" EOS
4. Noah - 12" EOS (assuming it holds pattern control down to ~1.2 kHz or less)
5. Zilch - Minimum 12" EOS (+cab roundover) assuming there's minimal on-axis notch
6. Erich H - either
7. JoshK (AudioJosh) - either with preference for 15" EOS
8. Bwaslo - 15" EOS, but either ok. 1" exit CD.
9. DS-21 - depending on cost (too rich for my blood and the incentive to swap out the 12" Tannoy DC's gets markedly lower), 15" EOS, 1" exit and throat-matched to a known-good CD (don't care which: B&C, BMS, Beyma, etc.)
10. P Monger - 15" EOS
11. LBDiver - Whichever will lead to it actually being built (current 15"-EOS w/ roundover looks good)
12. 12" EOS mjg100

14"

[quote=LTD02;19588909]you are saying that as long as it holds c.d. to 45 degrees, it is good.

the first time, my eye didn't catch that it was flat inside that region./QUOTE]

I missed it too; it does look very good out 45 deg.

jzagaja, what is the depth of your 15" EOS?

That's more of my concern w/bigger WG's than the width.

12cm deep with roundover 12cm.

Thanks, actually a few mm less than the XT1086.

Thought some of you might be interested in this. Make sure you check the pics link and the PDF (second link).

Then have a read of this.

LTD02, thanks for the links.

Those are amazingly priced since they're powered.

I like the K12's 75 deg coverage, I'm trying to minimize early reflections from a side window.

I wonder how good the drivers are, though presumably the DSP helps a lot.

It's interesting that they all seem to have the same XO.

You guys have been busy....get away for a weekend and there is so much to cover