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post #12001 of 12017 Old 01-22-2015, 03:37 PM
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I posted this question on my own thread but I think it's a more general question about how to best employ a SEOS in a room. I've tried searching this thread, and other forums, but it's hard to find a clear answer so I wonder if someone can confirm whether my thinking is accurate.

My current thinking is to build a SEOS10 over an 8" in a low profile on wall enclosure. A polar response of the SEOS10 was posted back in post #1393



As I understand it, this shows that +/- 22.5 degrees is approximately the range in which it is pretty much consistently at "full power" (i.e. minimal variation). As you get further off axis then there is some rolloff such that by +/- 45 degrees then you're 6dB down at the top end.

Applying this to an actual room then we can see the disperson of my L speaker below. The area I want to cover with sound is in blue, this requires output (from a flat on wall speaker) over 0-30 degrees. The area that produces 1st reflections off the ipsilateral wall is in red, this requires output from ~-25 to -50 degrees.



Therefore if I mount the speaker flat on wall then two things will happen

1) the 1st reflections from the L wall at the left most listening position will be strong
2) the direct sound at the right most listening position will be >3dB down

This makes me think the correct thing to do will be to angle the baffle by ~10 degrees (to point towards the opposing wall) which will mean

1) the listening position is in the -10 to +20 degree range == sweetspot!
2) the 1st reflections off the L wall will be in the -35 to -60 degree range (i.e. in the region of ~8-12dB down)

If this correct? Is there anything else I should consider with this positioning that I'm missing?
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post #12002 of 12017 Old 01-22-2015, 03:45 PM
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You're on the right track, but you haven't taken the idea far enough. If you toe the speaker in such that the nearest listener is outside that window by a few degrees you can enlarge the sweet spot considerably. The near wall reflections then get even lower in intensity.

Bwaslo wrote and posted a very good and compete discussion of time/intensity trading at diysoundgroup forums. Please read that.
http://www.diysoundgroup.com/forum/index.php?topic=20.0
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Last edited by HopefulFred; 01-22-2015 at 03:48 PM.
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post #12003 of 12017 Old 01-22-2015, 04:31 PM
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Thanks for the link. What happens when you put a C speaker into the middle of such a toed in LR?

Unfortunately I cannot accommodate that degree of toe in due to the on wall mounting & my depth constraints requirement to mount on wall. I think ~10 degrees is the most I can realistically manage (needs a 2" offset on the baffle given a 12" wide speaker)
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post #12004 of 12017 Old 01-22-2015, 06:11 PM
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That's why acoustic transparent screens are so helpful...you can build a baffle wall shaped how you need it, and it's hidden behind screen wall.
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post #12005 of 12017 Old 01-22-2015, 06:28 PM - Thread Starter
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as fred mentioned, these things do best when toed in or the speaker in front of the off axis listener will dominate and steer the sound off the center of the screen. not the end of the world if using a center though. this concept was discussed by klipsch in...1975 (see dope from hope 1975 https://community.klipsch.com/dope/D...0801_v15n2.pdf). for some reason we seem to need to keep rediscovering it. :-)

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post #12006 of 12017 Old 01-22-2015, 08:16 PM
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As someone who has a flat baffle wall, it's ok for movies with a center. For stereo music, my stand alone speakers can make a better image when toed in.
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post #12007 of 12017 Old 01-22-2015, 09:13 PM
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Quote:
Originally Posted by 3ll3d00d View Post
Unfortunately I cannot accommodate that degree of toe in due to the on wall mounting & my depth constraints requirement to mount on wall. I think ~10 degrees is the most I can realistically manage (needs a 2" offset on the baffle given a 12" wide speaker)
How about building out small false walls covered in decorative AT fabric at ~45 degrees in each of the bottom corners, with the L/R in the corners pointed at each opposite seat and the balance of the space serving as bass traps?

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post #12008 of 12017 Old 01-23-2015, 02:11 AM
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Quote:
Originally Posted by FriscoDTM View Post
How about building out small false walls covered in decorative AT fabric at ~45 degrees in each of the bottom corners, with the L/R in the corners pointed at each opposite seat and the balance of the space serving as bass traps?
I would like to do something like this however it requires some structural changes to the room (the door needs to move) so that is a 2-3 years down the line.
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post #12009 of 12017 Old 01-23-2015, 02:55 AM
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Quote:
Originally Posted by tuxedocivic View Post
As someone who has a flat baffle wall, it's ok for movies with a center. For stereo music, my stand alone speakers can make a better image when toed in.
does that mean the image is absolutely poor without sufficient toe in or that it is still good, just not as good?
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post #12010 of 12017 Old 01-23-2015, 03:28 AM
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Quote:
Originally Posted by 3ll3d00d View Post
does that mean the image is absolutely poor without sufficient toe in or that it is still good, just not as good?
Why not build the toe into the baffle as you previously mentioned? It doesn't have to be a steep angle, just enough to direct the image inward towards the listening position.
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post #12011 of 12017 Old 01-23-2015, 03:32 AM
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Quote:
Originally Posted by Tip24/96 View Post
Why not build the toe into the baffle as you previously mentioned? It doesn't have to be a steep angle, just enough to direct the image inward towards the listening position.
that's what I was thinking, something like this

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what I was asking, in the quoted post, was for a view on the relative quality of the stereo image when using markedly less toe in.
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post #12012 of 12017 Old 01-23-2015, 07:59 AM
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No the image is still good. Even venter channel fooling good sometimes. But not quite as wide or precise as my stand alone SEOS speakers with toe in. But I've never found it to be a factor when watching movies with LCR running. I only hear the difference in stereo.

Oh that's a completely flat baffle wall. No toe at all. So you'd be better off than me. FWIW, I'd give up my speakers before my baffle wall.

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post #12013 of 12017 Old 01-23-2015, 08:47 PM
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Was quite the undertaking to read all 400+ pages but I did it. Took me about two months of reading a little bit every day. Also looked into all the links to other pages and forums along the way. Reccomend everyone doing it, learned a lot in reading everyone's posts. You will have far less questions and more of the answers.

Erich thank you for everything you have done!

I will soon be purchasing some speakers from you for my home theater that I'm building in my unfinished basement. Once the basement get a little further along I'll start a build thread of my basement and show my integration of the speakers into the walls.
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post #12014 of 12017 Unread Yesterday, 08:12 AM
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Originally Posted by SilverSPL View Post
Was quite the undertaking to read all 400+ pages but I did it. Took me about two months of reading a little bit every day. Also looked into all the links to other pages and forums along the way. Reccomend everyone doing it, learned a lot in reading everyone's posts. You will have far less questions and more of the answers.

Erich thank you for everything you have done!

I will soon be purchasing some speakers from you for my home theater that I'm building in my unfinished basement. Once the basement get a little further along I'll start a build thread of my basement and show my integration of the speakers into the walls.
That's really awesome! I've read the majority of it "live" and I've also started at the beginning and gotten through the first 150 pages or so but to read the entire thing is quite the feet!
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post #12015 of 12017 Unread Yesterday, 11:25 PM
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Quote:
Originally Posted by SilverSPL View Post
Was quite the undertaking to read all 400+ pages but I did it. Took me about two months of reading a little bit every day. Also looked into all the links to other pages and forums along the way. Reccomend everyone doing it, learned a lot in reading everyone's posts. You will have far less questions and more of the answers.

Erich thank you for everything you have done!

I will soon be purchasing some speakers from you for my home theater that I'm building in my unfinished basement. Once the basement get a little further along I'll start a build thread of my basement and show my integration of the speakers into the walls.
Congrats! Lets hope
they become available soon again.
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post #12016 of 12017 Unread Today, 05:19 AM
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Do any of you fellows happen to have any experience building a slightly curved baffle wall? I am want to build a baffle wall in my ht room but make it with a built in curve in order to toe in my left and right speakers. If any of you guys have any experience with something like this, would you mind sending me a PM so that I can pick your brains and figure out how to do this properly?
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post #12017 of 12017 Unread Today, 05:21 AM
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Dedicated construction forum.

Also PM is insulting to some people, like you are special and only you are worthy of the information and time. You'll get a lot more information faster with a public thread in the proper area.

Typical baffle wall is mdf + drywall with GG in between layers.
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