Hey guys...we need a little rallying here... - Page 114

Those look like they would work phenomenally for surrounds! Besides the physical shape of the enclosure, what would be the pros and cons for surround duty when comparing a high efficiency 10" woofer + SEOS-12 versus the horizontal line array of 4 or 8 - 6" woofers paired up to an SEOS-12?

Well, the 10" would probably move more air (more x-max), and be an easier crossover to design.

The horizontal array of little woofers, mounted adjacent to the ceiling, would have little or no ceiling reflection issues, and would have horizontal pattern control to about an octave lower.

Does anyone know how, in fact, one would attach a speaker to a ceiling like that? Brackets at the edges?

The horizontal array sounds like the way to go. Besides higher efficiency, what would be the advantage of having another row of 4 - 6" woofers? Also, approx. how much higher efficiency will the 8 - 6" woofers have compared to 4 if we used the 91dB NS6?

I wouldn't attach it to the ceiling. If it were me, I would hang it off the wall studs and butt it against the ceiling.

Something like this but you would need to find one that fits perfectly.

Would that work in places where there wasn't a wall? Besides, it needs to be toed-in, at least for LR use.

Before I forget, here's the schematic for the Malcolm (v1) crossover:


The capacitors in the woofer circuit can be NP electrolytics.

The surrounds could be Jamie and Francis.

-Max

Bravo! Finally, someone else with my same crude tastes in TV shows.

Bwaslo, can you post the bill of materials (with PE part #s) for the the "Malcom" crossover?

266-552 Qty 2 1.5mH
255-044 Qty 1 0.8mH
255-026 Qty 2 0.25mH
255-038 Qty 1 0.55mH

027-940 Qty 1 22uF
027-406 Qty 1 0.47uF
027-438 Qty 1 25uF
027-427 Qty 1 6.2uF (use for 6uF)
027-410 Qty 1 1uF
027-364 Qty 1 150uF
027-354 Qty 1 50uF

015-.5 Qty 1 0.5 Ohm // Combine with 1.0 ohm to make 1.5 ohm
015-1.0 Qty 1 1.0 Ohm //

//These two could be replaced with an L-Pad if adjustment is wanted:
015-3.0 Qty 1 3.0 ohm
015-12 Qty 1 12 ohm (use in place of 13 ohm, close enough)

015-10 Qty 1 10 ohm
016-1.2 Qty 1 1.2 ohm
015-1.8 Qty 1 1.8 ohm
015-3.3 Qty 1 3.3 ohm

260-407 Qty 2 1.5"D Ports (shorten each by 1").

295-424 Qty 4 4" Designers' Series woofers
SEOS12 Waveguide Qty 1 (get from Erich)
Horn driver: Qty 1. Designed using "lesser" clone from Erich. "Better" clone will work nearly same (slightly smoother). B&C DE250 (294-605) will work as well also, though expensive.

Box made with 0.5" ply, baffle is 3/4" MDF. Outside dimensions are 21" wide, 12" high, 8" deep. Woofers spaced with 0.5" between edges. Box has internal window brace (with cutouts to allow air flow) between top section and woofer section. More bracing might be a good idea.

The preordering will go all the way up until they arrive. As far as I can tell, virtually all compression driver parts and other things should ship from one central location in about 10 days.

By the time they arrive, we should have a very good number of designs ready to go along with flat packs for those designs.

Basically.......it's gonna be very busy.


The guy from the big CNC company stopped down at my shop this past week to see what was going on. I gave him one of the plastic SEOS models for making the correct baffle cut outs. I think they will be recessed about 3mm to look their best. Making them 100% flush won't look as good because they were designed with a very slight roundover if you guys recall. We did that so they would look good just sitting on top of the baffle as well.

So many options...You must gain an anchorage to the wood framing.

You should include the method of support into the cabinet design for the most aesthetically pleasing solution.

One might use plywood to span across the joists. The plywood could be the same outline as the top of the speaker...or the edges could be concealed and enclosed by edges of the speaker which were extended up.
Is the space above an attic? Do you have access to the wood framing in that area? If so, wood blocking may be added in the attic.
I have wood blocking above my R & L bedroom speakers. The brackets are made from 1/2" pipe flanges, nipples and elbows.

The speaker leads run through the pipe.

The support system is not seen from the listening position.

I use heavy wall clips on the back of the speaker to attach through a wood adapter to the pipe/flange system.

I can remove the speaker by disconnecting the leads and lifting it (1/2") off.

The speaker bwaslo is dreaming up should be able to be mounted with a hook and pivot motion. Hook one edge in a positive way to carry a significant amount of the weight, then pivot up to final position and make the connection which secures it in place. It can and should be designed so one person can do it, unassisted.

Great!

It might help a full recess if you ease the sharp edge so that both rounded edges leave a "swale" to use landscaping terms

Here's where Erich and I disagree. I have the SEOS12 recessed 0.35", which looks good to me. I'm of the design philosophy that if you try to make something invisible it becomes even more noticeable. And if I'm going to the trouble of recessing a waveguide, I want people to say "hey, look, he recessed the waveguide!"

In woodworking there is a general rule about joints: You can either hide them or accentuate them. Making the right choice has a lot to do with the success of the project.

Why do you think carpenters invented trim mouldings?

Has anyone ever done ceiling-mounted L and R front speakers? Does it do ok on a stereo image for the sound to be coming from above? (If not, would adding a center channel mid-wall correct that?). The SEOS guides seem to make the sound origination less detectable than other speakers I've worked with (because of directivity?). Maybe that would help.

I'm still worked up about the idea of using "ceiling plane" mounting for speakers, it seems like it would fix a number of common speaker frequency response problems (ceiling slap, Allison effect, BSC, clear path to all listeners, taking up space in the room, horizontal directivity using the Malcolm trick, maybe even WAF if done tastefully with grills). But it is kind of unconventional. And not so easy to install up there.

Yes, Yes and ...no. The enclosure is a box Erich made for working up crossover designs. Rectangular, about 2.5 cuft (I think it was), well braced, nicely made from BB ply 3/4" thick. I routed out the WG to recess it. The woofer is a Deltalite 2512, working up the crossover on it now, getting ready to go outside and measure... waiting for coffee to hit me and provide motivation to get off the internet.

Back mounted woofer is ok, but then the box has to have a removable back or removable baffle.

That is what I have in the bedroom. They bracket the flat screen which is up against the ceiling to provide a comfortable viewing angle from bed.

Back in the day I hung speakers from the ceiling when we had a huge living room (24' X 16' X 10') in an older house. That worked very well.

I don't think it will work so well in ~smaller rooms.

On a trio of Ewave style but actively crossed speakers I'm working on I used the QSC horn and was able to fit the Faital pro 12pr300 through the horn cutout. It was actually rather easy to install the woofer.
I know the seos horn is a bit smaller but is the cutout for it large enough to fit a 12" woofer through it? If not will a 10" woofer fit? At least for me a flush mounted horn and a rear mounted woofer is the nicest looking configuration. This also naturally aligns the driver centers.

With the screen up high, I'm not surprised that works. Do you think it would go ok if the screen was at normal (seated eye-level) placement instead? Maybe with a center channel mounted at top of screen?

I can't say without trying. My center channel is below the screen, necessitated by the screen being so close to the ceiling. It works.

BEFORE anyone starts jumping to conclusions on the enclosure.....

The test box I made for Bwaslo is not going to be the design used. I made that box very quickly and I screwed up on the waveguide spacing with the woofer. We know this and I will build a better box very soon.


I do not care if we rear mount the woofers, but those were only done originally to get the vertical alignment close. The SEOS is shallow, so it's about the same depth as the VC on the woofers already. Making a box for a rear mounted woofer means the box has to have a removable back panel. That will add to the expense.




Everyone thought the SEOS should be designed to look good sitting flush right on the baffle. The debate stemmed around people wanting an easy way to mount the waveguide without worrying how to carve an oval shaped recess into the baffle. So the edges of the waveguide taper out, the edges are not 90 degress like a woofer basket.

The first 3-4mm is fairly straight before it tapers. So any recess over that depth will leave an air gap between the wood and the waveguide. I don't think it looks as nice because it appears like the recess was cut a little too big. It might sound great, but I personally would like a clean look as well.

I'll get pictures later.


No matter what, the waveguide will be recessed, even if it's just 3mm. The reason is because most will be using some type of gasket material and we don't want the waveguide to actually be sitting above the baffle after the gasket is used. If anyone wants it recessed deeper, that's fine with me. I just don't think they look quite as nice that way because of the air gap.

I'll have to check to see if a 10" will squeeze through the cutout of the SEOS-12. No way a 12" woofer would fit.

But the SEOS-12 won't be super easy to remove later down the road either. Because the consensus was no screw holes, or least number of screw holes, most will likely be using some type of silicone to get a really good seal around the waveguide and box. At least that's what I'm hoping to do.

Someone asked on another thread about harmonic distortion on the new "clone" drivers. (Erich: will you pick some names for these already?!? so I can refer to them without writing a paragraph each time? ).

The speaker I'm working on at the moment is in Erich's box with SEOS12 and Deltalite 2512. 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:


I don't have one of the "better" clones here at the moment to try, sorry. Not a lot of difference in the responses as you can see. 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. Cats here really like that test!

The price on the "lesser" model will be *significantly* less than a DE250. At least 50% cheaper. My main reason to get those was for surround models. But I think they will also be good enough for mains. I know my ears wouldn't be able to tell a difference.

I'll get a name figured out before the weekend is over.

I'm heading off to the shop, then to PE. It rained last night, so even though the employees are out and think I'm working, I'm going to play hooky and just do the work tomorrow. Way too many packages backing up that need to be taken care of.

How about "DIY Rally CD" in honor of all those who have inspired and contributed to this amazing project?

If you don't use screw holes and rely on silicone, that might affect the depth required for the depth of the recess; i.e. the recess depth seems to be affected by the decision to whether to use or not to use screws.