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Opinions on using waveguides as surrounds

post #1 of 34
3/13/12 at 10:39am
Thread Starter 
With all of the great SEOS projects coming up (thank you Erich and Bwaslo and everyone!) I'm curious as to how everyone views using these as surrounds. I have a pair of upgraded 4Pis as my mains and will be needing to upgrade my surrounds next. I've heard opinions of surrounds should not be horns/waveguides due to not wanting them to be directional, but more of an ambiance source. What are your thoughts? Maybe I should just build 2Pis? I'm so confused.
Or, maybe I should build another pair of 4Pis?


..... And all of this upgrading is lilmike's fault (in a good way) After building 2 of his F20s, they were so beastly that I needed to upgrade my mains to 4Pis. Now I'll need to be upgrading my surrounds ..... Oh the dilemmas
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post #2 of 34
3/13/12 at 10:50am
Quote:
Originally Posted by Maxjr View Post

With all of the great SEOS projects coming up (thank you Erich and Bwaslo and everyone!) I'm curious as to how everyone views using these as surrounds. I have a pair of upgraded 4Pis as my mains and will be needing to upgrade my surrounds next. I've heard opinions of surrounds should not be horns/waveguides due to not wanting them to be directional, but more of an ambiance source. What are your thoughts? Maybe I should just build 2Pis? I'm spool confused.

..... And all of this upgrading is lilmike's fault (in a good way) After building 2 of his F20s, they were so beastly that I needed to upgrade my mains to 4Pis. Now I'll need to be upgrading my surrounds ..... Oh the dilemmas

I say go for it!! Take a look at my build to see what I'm using. My current setup to my is the absolute that I've ever put together.

Some here may have a different opinion but ultimately it's up to you. For me in the theater, I'll never go back to consumer products (except for the Klipsh THX setup) and I'll always go horn/waveguide on the rears.

As for the rest of the house... that's a different story.
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post #3 of 34
3/13/12 at 11:09am
I did a lot of experimenting with various surround types a while ago and the WG types I built for that were my most strongly preferred option. I've put my money where my mouth is with this and bought 4 plastic SEOS12 for the surrounds here.
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post #4 of 34
3/13/12 at 12:18pm
Thread Starter 
Quote:
Originally Posted by chucky08016 View Post

I say go for it!! Take a look at my build to see what I'm using. My current setup to my is the absolute that I've ever put together.

Some here may have a different opinion but ultimately it's up to you. For me in the theater, I'll never go back to consumer products (except for the Klipsh THX setup) and I'll always go horn/waveguide on the rears.

As for the rest of the house... that's a different story.

Hey Chucky! I tried looking for your build through your started threads, but could not find it. Could you give me a link? Thanks in advance.
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post #5 of 34
3/13/12 at 12:23pm
Thread Starter 
Quote:
Originally Posted by A9X-308 View Post

I did a lot of experimenting with various surround types a while ago and the WG types I built for that were my most strongly preferred option. I've put my money where my mouth is with this and bought 4 plastic SEOS12 for the surrounds here.

This is very good to hear and encouraging! I love to build and try new things, and I really want to try out those plastic SEOS-12 waveguides. Especially if they'll work phenomenally as surrounds. I just have to make sure I have enough saved to complete building either 2 or 4 of them all the way (SEOS-12, midwoofer, compression driver, crossover, and box).
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post #6 of 34
3/13/12 at 1:14pm
What is your personal preference? Do you prefer the intensity of ping-pong surround, or, a more relaxed ambient environment?

Video concerts are my priority and I prefer an audience perspective (ambience) produced by wide-dispersion surrounds. Others like more precise localization of gunshots, sitting in the middle of the band, etc.

Determine your objectives and go for it!
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post #7 of 34
3/13/12 at 1:25pm
I would think with a waveguide the sweet spot would be wider than a traditional bookshelf, therefore making it less point source. On the other hand, im toying with the idea of keep my coaxials for the rears, and putting the aperion bi/dipoles back in as side surrounds so you get the best of both worlds I really think THAT is the ticket tbqh
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post #8 of 34
3/13/12 at 1:45pm
Waveguide surrounds can work quite well but there are some caveats related to placement. First, they will have a fairly narrow vertical dispersion and this can be an issue if you want to cover a bunch of seats and the surrounds are close to some of the seats. I would want meet the following criteria:

1. You have at least 20" between the side wall and nearest seat.
2. The ability to place the surround high on the wall and angle it down.
3. Wide vertical nulls based on the crossover design and driver placement.

If you can do this, then it will work quite well. If you can't meet those requirements I'd suggest something like a pro coax or typical dome setup.

If you are sketchup handy, you can mock up your room and draw out the coverage pattern of the horn and how it will cover your seats based on different placements. I would estimate a vertical pattern of about 40 deg for the SEOS since there is some narrowing in the vertical.

I'd also suggest using something like a SEOS-12 and 10" woofer combination instead of a 12 or 15" woofer because it will give you a closer CTC spacing and allow for wider null angles with the same crossover point. Something like Bwaslo's recent design in the SEOS thread might work well since it is a 10" woofer and a 1200hz crossover. That should space the nulls very wide which is more important in a surround than in a LCR speaker.
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post #9 of 34
3/13/12 at 2:00pm
Thread Starter 
Quote:
Originally Posted by pnw View Post

What is your personal preference? Do you prefer the intensity of ping-pong surround, or, a more relaxed ambient environment?

Video concerts are my priority and I prefer an audience perspective (ambience) produced by wide-dispersion surrounds. Others like more precise localization of gunshots, sitting in the middle of the band, etc.

Determine your objectives and go for it!

I suppose if I had to choose between the two, I'd go for intensity and non-localization. Not quite sure though since I've never experienced a waveguide surround. Currently I have Energy RC-Rs which can be either bipole or dipole. I'm thinking I'll just go for the SEOS-12 surrounds and compare with my current setup.
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post #10 of 34
3/13/12 at 2:16pm
Thread Starter 
Quote:
Originally Posted by coctostan View Post

Waveguide surrounds can work quite well but there are some caveats related to placement. First, they will have a fairly narrow vertical dispersion and this can be an issue if you want to cover a bunch of seats and the surrounds are close to some of the seats. I would want meet the following criteria:

1. You have at least 20" between the side wall and nearest seat.
2. The ability to place the surround high on the wall and angle it down.
3. Wide vertical nulls based on the crossover design and driver placement.

If you can do this, then it will work quite well. If you can't meet those requirements I'd suggest something like a pro coax or typical dome setup.

If you are sketchup handy, you can mock up your room and draw out the coverage pattern of the horn and how it will cover your seats based on different placements. I would estimate a vertical pattern of about 40 deg for the SEOS since there is some narrowing in the vertical.

I'd also suggest using something like a SEOS-12 and 10" woofer combination instead of a 12 or 15" woofer because it will give you a closer CTC spacing and allow for wider null angles with the same crossover point. Something like Bwaslo's recent design in the SEOS thread might work well since it is a 10" woofer and a 1200hz crossover. That should space the nulls very wide which is more important in a surround than in a LCR speaker.

This is good news! Thank you for your caveats. I meet all of them. I currently have about 4' from the surround placement to the nearest seats. They are also placed about 2.5' up and angled down.

I really like the idea, price, and size of pairing the SEOS-12 and a 10" pro midwoofer. With the 40 degree vertical, is the horizontal around 90 like the H290 that Wayne P uses? (admitingly, I Can't recall the SEOS dispersion pattern)
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post #11 of 34
3/13/12 at 2:17pm
Quote:
Originally Posted by pnw View Post

What is your personal preference? Do you prefer the intensity of ping-pong surround, or, a more relaxed ambient

I didn't find it sounded ping pong at all, rather well defined and sharp instead of a blamenge.
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post #12 of 34
3/14/12 at 7:34am
Quote:
Originally Posted by Maxjr View Post

Hey Chucky! I tried looking for your build through your started threads, but could not find it. Could you give me a link? Thanks in advance.

http://www.avsforum.com/avs-vb/showt...ht=qsc+sc+2150

Sorry about that... posted from my phone and could not search for the thread at the time.
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post #13 of 34
3/14/12 at 11:29am
Thread Starter 
Thanks for the link. Your theater looks great! I hope my room can hold a candle to yours eventually
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post #14 of 34
3/14/12 at 11:50am
Would there be any benefit to mounting the waveguides vertically versus horizontal for surrounds, and angle them down?
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post #15 of 34
3/14/12 at 12:10pm
Quote:
Originally Posted by Erich H View Post

Would there be any benefit to mounting the waveguides vertically versus horizontal for surrounds, and angle them down?

I can't see any advantages with that.
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post #16 of 34
3/14/12 at 1:07pm
Quote:
Originally Posted by Erich H View Post

Would there be any benefit to mounting the waveguides vertically versus horizontal for surrounds, and angle them down?

Quote:
Originally Posted by A9X-308 View Post

I can't see any advantages with that.

More dispersion? since most WG's have less vertical sweet spot vs horizontal, mounting vertically would fix the issue, or at least make it a little better.
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post #17 of 34
3/14/12 at 1:07pm
Thread Starter 
Quote:
Originally Posted by Erich H View Post

Would there be any benefit to mounting the waveguides vertically versus horizontal for surrounds, and angle them down?

The main difference I can see is the 40 degree x 90 degree dispersion pattern will be flipped if mounted vertically.
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post #18 of 34
3/14/12 at 1:16pm
My rear seats are directly below my rear surrounds and about 5 feet up. Its the best I can do because I have vaulted ceilings and the couch backs to the next roo. I was thinking I would build the rear surrounds poitng straight down. Imagine the fronts but mount to the rear wall with the bottom attched to the wall. I don't know how I could angle enough to be in the cone. I currently have dipoles and don't get much surround sound. I personally love the THX etc. intros with the sound bouncing everywhere. Do you all think I'm off base with my logic? If so what are your suggestions. I guess I better order 4 more SEOS 12's. I just sold another projector and screen so I better spend it before my wife does.
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post #19 of 34
3/14/12 at 1:40pm
Quote:
Originally Posted by Maxjr View Post

This is good news! Thank you for your caveats. I meet all of them. I currently have about 4' from the surround placement to the nearest seats. They are also placed about 2.5' up and angled down.

I really like the idea, price, and size of pairing the SEOS-12 and a 10" pro midwoofer. With the 40 degree vertical, is the horizontal around 90 like the H290 that Wayne P uses? (admitingly, I Can't recall the SEOS dispersion pattern)

It is approximately 90deg in the horizontal. It ranges from about 50deg to 35deg in the vertical as frequency goes up IIRC. I'd suggest mocking it up in sketchup or on paper to see how it covers your seats.

Quote:
Originally Posted by Erich H View Post

Would there be any benefit to mounting the waveguides vertically versus horizontal for surrounds, and angle them down?

You could try using the waveguide in a vertical orientation with an 8 or 10in woofer. You would probably cross somewhere around 900-1000hz. I'm not sure how well it would work, but JBL has done it in their Array series. I think you would end up getting a significantly different directivity. You wouldn't hold horizontal pattern very low (~1500-1800hz) but it would be narrow above that. You would need the lower cross to keep because the nulls wide enough.

I haven't tried it and it would be neat to try, but I'd probably suggest sticking to horizontal if you want a more predictable outcome.
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post #20 of 34
3/15/12 at 12:10am
Quote:
Originally Posted by beastaudio View Post

More dispersion? since most WG's have less vertical sweet spot vs horizontal, mounting vertically would fix the issue, or at least make it a little better.

Except in some really oddball room arrangements, I don't see that the narrower horizontal dispersion is of benefit. And I did consider a second row on a riser.
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post #21 of 34
3/25/12 at 11:46am
Thread Starter 
I think I'm sold! Anyone else currently using waveguides as surrounds? I wonder how another pair of 4Pis as surrounds would sound?
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post #22 of 34
3/25/12 at 1:07pm
Quote:
Originally Posted by Maxjr View Post

I think I'm sold! Anyone else currently using waveguides as surrounds? I wonder how another pair of 4Pis as surrounds would sound?

Good lord! why not? I wish I had a wide enough room to do so, but theres no way!
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post #23 of 34
3/25/12 at 1:43pm
Thread Starter 
Quote:
Originally Posted by beastaudio View Post

Good lord! why not? I wish I had a wide enough room to do so, but theres no way!

Actually, after further thought, there is no way I could hang these 4pis on my walls. They're close to 70 lbs and are huge (26.5" x 18.5" x 14.5") I think smaller 10" surrounds with SEOS12s and copy DE250s would be more suitable.

Edit: as a side note, I love my new 4Pis to no end. I can't imagine getting any better. They have ZERO WAF, but are exceptional at what they were designed to do: recreate accurate sound.
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post #24 of 34
3/25/12 at 1:54pm
There will be a surround speaker using the SEOS-12. I'll be cutting the test box this week.
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post #25 of 34
3/26/12 at 10:13am
Thread Starter 
Quote:
Originally Posted by Erich H View Post

There will be a surround speaker using the SEOS-12. I'll be cutting the test box this week.

That puts a huge smile on my face! I can't wait to see the build. It should be awesome!
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post #26 of 34
3/26/12 at 10:22am
I am using waveguides on all 7 channels - CHT speakers - my surrounds are about three feet above seated ear level for the front row, two feet for the rear row (riser), and all seats are at least 4 feet from the surrounds. I also pre-ordered 3 of the plastic SEOS-12 waveguides, and will be building LCRs with them.
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post #27 of 34
3/27/12 at 5:42am
What is the general depth you think SEOS 12 surrounds will be?

I was trying to keep within 6". Then I would recess the speaker into the wall, with a backer box made of double 1/2" MDF and green glue. That would flush mount my surrounds with my 2" thick acoustical treatments. Paul Spencer (AVS) used some vented 8" B&C 8PS21s that reach down to about 90Hz. There was not a tweeter integrated into that design. Although an 8" would be pretty, if not too, small for a SEOS 12.
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post #28 of 34
3/27/12 at 5:45am
A SEOS12 and its driver will put the box depth at about 8".
I'm finishing up on a center channel design using SEOS12, and it is about 21Wx12Hx8Deep
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post #29 of 34
3/27/12 at 6:50am
Quote:
Originally Posted by bwaslo View Post

A SEOS12 and its driver will put the box depth at about 8".
I'm finishing up on a center channel design using SEOS12, and it is about 21Wx12Hx8Deep

Cool. I'll bet that's a huge hit too. Dual 6" mid-woofers? Which ones? Ported or sealed? I'd love to hear something like that with a pair of td6m's.

-Nate
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post #30 of 34
3/27/12 at 8:12am
Nope, using a row of four DS115-8 in a horizontal shaded line array. trying to keep height down.
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