Hey guys...we need a little rallying here... - Page 236

Nick,
These boxes are only 2 cu'. No I can't imagine.
In this photo I am about to add round-overs (3/8" to the baffle edges, and 5/8" for all other edges)


Here they are with roundovers, and latex spackle (a pre-Duratex step) to fill some belt sander gaffs


So last week, I mentioned some Beta-logos my son made on a 3D printer.
I made a template to allow me to route some recesses for mounting the logos


And ready to route


Here's the boxes ready for Duratex, with the a logo test-fit




Filled the stand legs with sand, this took the stand weight from 25 lbs each to 40 lbs


So What's Left?
Build the crossovers,
Duratexing,
Assembly
Test, Listen, and Measure

It's been about a year since we started the preorders for the SEOS-12 done in plastic. It's only been about 9 months since we had them available and you can see how the DIY Community has stepped up with great speaker designs.

So does anyone want to do one or two more sizes?

I sold a landscaping truck a few months ago that wasn't being used very much. I put some of that money towards the larger subwoofer flat packs, but it came back in pretty quick. So I've got about 50% of what we'd need for more plastic models.

I'm thinking about one of those Kickstarter projects. Has anyone here ever worked with one of those before? Or is anyone willing to help with some of the wording or layout of the project? I'm only thinking about it right now, but with just a little help, I would definitely try it. We could shoot for the SEOS-10 and SEOS-15 at first. If a certain number was reached, I'd also try for the SEOS-18.

My weakness would be in wording everything properly to make it sound it's best. But I know there are a few guys here that could do that very quickly. This could be a really neat way to top off the whole project.

Any thoughts.
Edited by Erich H - 3/4/13 at 7:33am

Erich,

Are you caught up with packaging and shipments?

Have you listed all the baffles and flat packs for SEOS and subwoofers?

I'm out about a week on packaging unless there's something custom going on, which has been fairly normal for a while now. I'm not going to list all the different baffles because some were only done in very small quantities.

As time goes on, if there's a demand for certain box sizes or baffle shapes, I can get more cut. 3-5 here and there is no big deal. But if demand goes up, I have to get 30-50 of them cut at a time. So unless that happened, it's not worth listing any of the 'custom' stuff. It just adds confusion to what baffles go with what boxes.

Kudos on those logos!
I've got a 3 cu ft sub box Saturday for 15" SI D2, and soon a 2.25 cu ft sub box for my 12" Ultimate.
Any chance on having a small production run on them so we can proudly insert them into our boxes?
I'd take 2 of the "DIY Sound Group"....Brand marketing 101 stuff, nice to see.

Thanks Guys!

I am not sure how many I can get made (these come from a shared 3D printer at my sons school). We are going to make some subtle changes to the design. The first batch will be reserved for Erich , myself, and a key designer that consulted on my builds.

Not sure how many will be possible beyond this?

I will be sharing the cad-cam software with Erich. I want Erich to have the control and say-so on any future quantities that might be possible.

Great work Cuzed! I really like those stands. Have you decided on what color to "dip" the logo's to make the edges stand out?

Thanks Drewmc,

For the Maroon SEOS logo , I'm going to first try a gold or bronze color (hope it's not too tacky)?

What effect would a deep recess have on the waveguide? Like a full 0.75" recess with roundovers? IDK enough about waveguide performance to know what happens beyond the waveguide face. My guess based on omni tweets is some type of diffraction. However if I don't recess fully the woofer sits proud anyways which also could be a diffraction source, right?

Any thoughts or data on this type of install?

Hey Nick. Hmm, my first thought is that it would change the acoustic centers. If the z-axis changes it would affect phase. I believe with omni's x,y,z are set to zero (flush to baffle) and the woofer's offset is adjusted to achieve phase allignment. I would refer to Bill's pic of the summing curve phase offset calculator in the *.zip he provided in that thread. You would take the measurement of the tweeter from woofer front and subtract from the woofer's axis to get z-axis correction. If he doesn't chime in here, maybe bump that thread.

-Nate

Hey RB,

I was assuming I'd need to recess the woofer the same distance to keep them mounted on same plane?

Ah, are you rear mounting the woofer? In that case as long as the offset doesn't change, then perhaps diffration will be the only issue. I thought the roundover on the waveguide was important in transitioning lower frequencies to the baffle and why they are not flush (3mm). Maybe wrong on that though.

I think you'd get quite a bit of diffraction, much more than from a proud woofer frame. You want to rear mount everything?

That would be interesting ...

A full on assault on diffraction, with massive exterior round-oversrs, and a rear mounted LF driver with a tightened center-to-center placing the woofer up and somewhat behind the waveguide flange, with it's transition to the baffle face as rounded and diffraction free as one could manage.

Just thinking aloud ... not even sure what's measurable, and regarding what is measurable, what's audibly important or not. I've experimented with diffraction, and audibility ... however never verified with any real effort and measurements.

Any interest in getting some of the other SEOS sizes done in plastic?

They should all be available in plastic black. Since they perform the same, we don't really "need" resin or fiberglass, and it would cut down on build costs.

Yes! The 15 inch version for sure.
_____________
Best Regards,
Carl Huff

About z-axis alignment :

If you're using a measuring setup other than omnimic (or even if it is OM) and ARE using PCD, you can align via Jeff Bagby's method. Set the Mic on the desired axis and then measure three times: woofer-only, tweeter only, and both together. You need phase responses so if your measuring setup doesn't give that, use a hilbert process to generate it for woofer and for tweeter.

Then import both tweeter and woofer files into PCD, disable crossovers in it, and adjust the tweeter-to -woofer z offset difference till the sum looks like your measurement of both playing (most sensitive where the tweeter and woofer curves cross). Leave the z numbers there and start working on the crossovers.

The process in OM is basically equivalent.

I agree, but it would be very expensive to have them all produced in plastic.

Out of these, SEOS-AT1, SEOS-10, SEOS-15, SEOS-18, and SEOS-24, it would seem the next logical choice would be the 15. Just on the Poland GB alone there are three people building around the SEOS-15 (it would be excellent if those designs were made public), and Bill's TD15M/SEOS-15 design, it gives people more options/design choices. As you know, I'll have a design for the AT1 and I could probably work up one with the SEOS-10. So, maybe folks who want something compact would be interrested in some smaller plastic wg's.

-Nate

That's exactly how I'm doing it. 3 measurement method w/OM using the overlay feature in PCD. You don't really need accuate measurements for the z-offset calc either. Pretty cool.

?

Hey Tux, Jeff B. disscusses it here: http://techtalk.parts-express.com/showthread.php?227206-How-to-use-OmniMic-and-PCD-to-find-the-Relative-Acoustic-Offset

It's just to get the offset # withwhich to apply to the final xo simulation (with accuate measurements) in PCD.

I'm aware of the method, it's actually David Lee Ralph's method (imo), just don't get why you would use a less accurate measurement to derive the z offset. I usually take it while taking the rest of my measurements and it's equally accurate. Not a big deal.

Certainly, yes. I think Jeff was just saying it could be done that way to demonstrate the methods' simplicity. I definately intend to start with accurate acoustic measurements and go from there.

Ok gotcha.

Is there a reason this is better than the much easier and seemingly less error-prone method of inverting one of the drivers and adjusting relative position for the deepest notch at XO?

That would be working from the other way. It is assumed (in what I described) that both drivers are mounted where they will stay and you're trying to get their depth difference relationship into PCD for proper crossover simulation.

If you have measurements that include true phase and delay, you wouldn't have to do that, it would be all accounted for in the phase measurement. Praxis and LAUD worked that way, and I think REW can work that way (if you've got a cooperative soundcard and don't get ground noise problems. OmniMic does measure true phase but with an unknown absolute delay (since the microphone doesn't know when the signals left the speaker, a side effect of having a system that doesn't require you to hook up computers to the measured speaker). So the delay relationship has to be accounted for with methods like this one.

The invert-for-notch trick is what you do while working on a crossover in a simulator (which has to have the depth relationship modeled correctly first ... see above!). Or when you have freedom of moving the waveguide forward and back to find a happy position for lobe pointing. That only works right when the levels are about matched already at the crossover frequency and you've got all the phase shifts and delays dealt with in the crossover components. It's to make sure that the lobe is pointing forward. A nice thing about doing a Synergy horn is you don't have to care about that, the one lobe always points forward.

+1 for 15.0" plastic!

Thanks for the explanation, Bill; I missed that it's somewhat of a chicken/egg scenario.