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SEOS-12 waveguide builds vs. QSC 152i builds for high mounted in-wall speakers.

2276 Views 17 Replies 4 Participants Last post by CZ Eddie, Feb 20, 2014

CZ Eddie

Discussion Starter · Feb 19, 2014

Guys, I'm building in-wall speakers for my Cousin. Got the final approval this afternoon on a design.

30”H x 15”W x 20”D are the available dimensions.

What sucks, is the ONLY place these are allowed to go, is in-wall, about 1/2 way up the wall (12' ceiling?)

The bottom of the speaker cabinets would be exactly 5' above the floor.

So, which waveguide do you think would work better?

I already have some QSC 152i's on-hand.

But the price of buying the SEOS 12 is a non-factor, thanks to Erichs great pricing.

So, I'm thinking of either a Fusion 12 build using the SEOS, or an Econowave Deluxe type build using the QSC.

Which do you think will give better off-axis performance?

Seating location is 160" away from the wall.

In-wall locations are straddling an 80" TV above the fireplace/cabinet.

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1 - 18 of 18 Posts

LTD02

· #2 · Feb 19, 2014

not sure where the forward lobe is on those speakers. might work best upside down in this app. toed in possible?

CZ Eddie

Discussion Starter · #3 · Feb 19, 2014

The only toe-in that could be done, would be within the wall, built into the cabinet itself.

So there would be a small lip it would have to fire past.

Such as in the drawing I posted below.

Brown = woofer.

Grey = inside of the enclosure.

Green = Wall surface

Blue = Room interior

Another thing that concerns me is cancellation bounce. These speakers are being mounted almost exactly in the middle of the wall, halfway between the floor and ceiling.

A helpful poster on DIYaudio had this suggestion:

Quote:
Originally Posted by Greebster;3825530

The bounce can be greatly reduced if one is to use two drivers one much lower than the other, like in a 2.5way the added 0.5 helper woofer is used. Space this at 1/4 wavelength at the crossover frequency. Done. Loading bass into a room from the mid height is not a bad thing. If the helper woofer is placed above, within 1/3 distance of the wall to ceiling adds better correction for room modes per Geddes.

Best to sim first with REW or Geddes room mode sim.

Dangit, I use REW all the time but never heard of that functionality. I'll have to research it later today.

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tuxedocivic

· #4 · Feb 19, 2014

Have a look here: http://www.diysoundgroup.com/forum/index.php?topic=127.0

I had a guy over on Sunday to here a variant of these. Username Tyee. PM him if you'd like, although he didn't hear exactly that speaker but a variant. I just can't help but fiddle. The one he heard needs some changes. The one in that thread is better. I now use the DNA-360 for the one in that thread. And it has a very tall vertical lobe.

CZ Eddie

Discussion Starter · #5 · Feb 19, 2014

Quote:
Originally Posted by tuxedocivic /t/1518671/seos-12-waveguide-builds...r-high-mounted-in-wall-speakers#post_24379918

Have a look here: http://www.diysoundgroup.com/forum/index.php?topic=127.0

I had a guy over on Sunday to here a variant of these. Username Tyee. PM him if you'd like, although he didn't hear exactly that speaker but a variant. I just can't help but fiddle. The one he heard needs some changes. The one in that thread is better. I now use the DNA-360 for the one in that thread. And it has a very tall vertical lobe.

Hey that's awesome. I had been worried about an in-wall crossover.

Those are 10" drivers? Looks like a really nice setup.

I got approval to get the $640 Fusion 12 Tempest for him. That uses a different woofer though, slightly larger Delta Pro-12A. Would your in-wall crossover work okay with that woofer?

I wanted to go as big as possible due to wanting as much full-range bass as possible for two-channel duty without sub.

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tuxedocivic

· #6 · Feb 19, 2014

My XO won't work with that Tempest woofer. And the 10" woofer I used won't make much bass. Sorry.

You sure the wall has enough depth to fit the 12" woofer and provide enough clearance around the pole vent? The SEOS12 and DNA-360 need an honest 5.5" iirc.

CZ Eddie

Discussion Starter · #7 · Feb 19, 2014

We have mega depth available. These are the available dimensions.

30”H x 15”W x 22”D

That's like 4 cu.ft. interior volume. Though I think the 12 only requires 2 cu.ft.

The enclosure will be made from 3/4" Birch wood or something similar, with a double front baffle thickness.

I'm thinking about just keeping the regular BSC since we may need a natural midbass boost due to the speaker being exactly halfway between floor and ceiling.

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tuxedocivic

· #8 · Feb 19, 2014

Ah ok you're good there then. The tempests use a heavy dose of baffle step compensation, so in wall like that, you should expect to eq out about 5db around 100hz (generalizing here). If you can't it's likely they'll sound very bloated.

CZ Eddie

Discussion Starter · #9 · Feb 19, 2014

Thanks for the info.

He has Audyyssey (sp?) EQ on his Denon AVR. But I have a MiniDSP we can use if it ends up being too bloated somewhere.

I'm still trying to figure out the SEOS-12 dispersion though. The QSC is 90° x 60° and I think the SEOS may be quite a bit less.

The QSC may work better for my Cousins application since the horn throat will be about 5.5' above floor level (if the enclosure is mounted upside down).

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tuxedocivic

· #10 · Feb 19, 2014

I wonder if Jeff Bagby has vertical measurements for the Tempests. It's not so much the waveguide as the XO region that will likely have a null in it. I've measured the vertical response of the SEOS 12 and its plenty wide and smooth. If Jeff has the verticals, you can figure out really quick if you'll be sitting in a null.

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LTD02

· #11 · Feb 19, 2014

the seos is about 90 horizontal, maybe a hair narrower:

http://www.avsforum.com/t/1291022/hey-guys-we-need-a-little-rallying-here/

Reactions: 1

CZ Eddie

Discussion Starter · #12 · Feb 19, 2014

How would you guys compare the SEOS 12 to the Econowave Deluxe which uses the QSC 152i, DE250 and 3012LF woofer?

The Deluxe probably doesn't have as much bass.

Otherwise, they both look kind of similar. With the Deluxe costing about $140 more and not coming with a pre-cut bezel.

http://techtalk.parts-express.com/showthread.php?215536-Flex-Your-PCD-Mettle/page2&p=1624578#post1624578

LTD02, that makes sense. I found somewhere else that it was 40* vertical. So that would put it at a 90x40 compared to the QSC at 90x60.

I'm not sure anyone will be sitting right under the speakers though, which is probably where the 60* would help more.

Closest sitting position would be about 110" and default sitting is 160" away.

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noah katz

· #13 · Feb 20, 2014

I'm going to mount my SEOS L/R high on the wall for logistics reasons in my multi-use room, and was thinking I would steer the vertical lobe down toward the listening area by rear-mounting the woofer to move it inward.

For example, if c-c is 9", mounting the woofer 1" rearward from nominal tips the lobe down by arctan (1/9) = 6.3 deg

CZ Eddie

Discussion Starter · #14 · Feb 20, 2014

Wild. And neat idea!

I saw someone else who thought they would do the same thing (for highs) by mounting the waveguide forward on the enclosure, but he was told by an EQ designer (Jeff B?) that it wouldn't help.

But your idea is for midrange, not highs.

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noah katz

· #15 · Feb 20, 2014

Good point on the highs.

Another option you can do since you have the depth is to tilt the whole box down, and/or put the WG below the woofer.

CZ Eddie

Discussion Starter · #16 · Feb 20, 2014

Quote:
Originally Posted by noah katz /t/1518671/seos-12-waveguide-builds...r-high-mounted-in-wall-speakers#post_24381939

Good point on the highs.

Another option you can do since you have the depth is to tilt the whole box down, and/or put the WG below the woofer.

I never thought about tilting the box down. It's a neat idea.

And if the Waveguide were on the bottom, it may not cause too many diffraction issues for the left & right side lips.

noah katz

· #17 · Feb 20, 2014

Quote:
Originally Posted by CZ Eddie /t/1518671/seos-12-waveguide-builds...h-mounted-in-wall-speakers/0_50#post_24382060

And if the Waveguide were on the bottom, it may not cause too many diffraction issues for the left & right side lips.

? Tilting the box to point down means the the bottom of the box is further into the wall

CZ Eddie

Discussion Starter · #18 · Feb 20, 2014

Quote:
Originally Posted by noah katz /t/1518671/seos-12-waveguide-builds...r-high-mounted-in-wall-speakers#post_24382717

? Tilting the box to point down means the the bottom of the box is further into the wall

Yes, I know that and know what I was thinking.

But somewhere along the way my up & down got crossed.

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