SEOS Recommendations for Large Home Theater - AVS Forum
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post #1 of 47 Old 06-03-2013, 02:48 PM - Thread Starter
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I'm working on a dedicated room that is roughly 18' 6" x 30', and I've read great things about the SEOS designs. I've been reading some of the threads, but the information is very spread out, so I'm having a hard time figuring out which speakers are best for which applications.

Could you guys get me going in the right direction for LCRs as well all the surrounds? I'm planning a 7.x setup and I'd like to experiment with 9.x and 11.x as well. I'm planning at least two subs if I go with a horn design like the F20 and possibly more if I go sealed. So I think the low end will be well covered.

Any suggestions are greatly appreciated!

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post #2 of 47 Old 06-03-2013, 02:49 PM
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What is your budget?
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post #3 of 47 Old 06-03-2013, 02:52 PM - Thread Starter
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Wow, that was quick smile.gif

Can't believe I forgot that. Budget is flexible, but maybe $200 - $500 per speaker. I'd like to stay on the low end of that if there's little difference in performance for a large cost difference.

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post #4 of 47 Old 06-03-2013, 02:53 PM
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Fusion-15 Sentinel's.

http://www.diysoundgroup.com/waveguide-speaker-kits/fusion-series-kits/fusion15-kit.html
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post #5 of 47 Old 06-03-2013, 03:01 PM - Thread Starter
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LCR and surrounds? Can I go with a cheaper surround and still get a good match between them and the LCR? What about the crossover?

What about those makes them a good fit for my room? I'm just curious about the pros and cons to the different kits.

Thanks for feedback!

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post #6 of 47 Old 06-03-2013, 03:02 PM
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They have the most capability overall compared to the other kits so it would be recommended to use them for at least LCR duty in a room your size. You could use a smaller kit for the surrounds, sure.
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post #7 of 47 Old 06-03-2013, 03:15 PM - Thread Starter
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What about a crossover?

Would these work for surrounds with the kit you recommended? Obviously the price is attractive for these smile.gif Would there be a noticeable tonal shift between these two different speakers? Should I go with one of the 8" or 10" designs for the surrounds, instead?

Thanks again for the info!

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post #8 of 47 Old 06-03-2013, 03:24 PM
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How would you implement them, ... free standing, in a baffle-wall, in a screen-wall?

edit; I just clicked, and quickly examined your HT images, I'll look in there for more details, nice size room

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post #9 of 47 Old 06-03-2013, 04:29 PM - Thread Starter
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I was planning for them to go behind an AT screen wall. I could do baffle wall, but I'm a little concerned about getting the placement just right since the baffle wall would lock me in on the location.

I'm open to suggestions on he placement! Also, I think I'll need to look at the smaller options for the surrounds. A cabinet for a 15" speaker will probably be pushing it for hiding it in a column. Suggestions there?

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post #10 of 47 Old 06-03-2013, 04:34 PM
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It's not a SEOS-branded project but it should mate well with the Sentinels.

http://www.avsforum.com/t/1353658/budget-eminence-coaxial-surround-build

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post #11 of 47 Old 06-03-2013, 06:21 PM
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I use and like the B&C 8CX21 coax's for surrounds

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post #12 of 47 Old 06-03-2013, 06:44 PM
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Noah, do those come with a crossover? Also what kind of enclosure do you use?
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post #13 of 47 Old 06-03-2013, 06:48 PM
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Edit, had a brain fart!
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post #14 of 47 Old 06-03-2013, 07:05 PM
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You're wrong smile.gif

It has a compression driver tweeter.

Best price for it I found was at prosoundservice.com, ~$220 per channel with the B&C XO.

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post #15 of 47 Old 06-03-2013, 07:11 PM
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I will second the Sentinels for your room and budget. It looks like you have ample room to go any route you want with the surrounds. If I had such a room I would do all 7/9/11 channels with the same speakers. You can always get creative with the Height and Width channels but for the relatively low cost of building the Sentinels I would be all in. You could disguise the Side and rear surrounds as columns and completely hide your LCR and Height speakers. The columns wouldn't have to be crazy wide as the Sentinels come in at 17.25" wide.

I see two columns on the sides and two in the rear. The two closest to the screen would house your Width speakers and the other two house the L&R side surrounds. The two on the back wall would house the L&R back surrounds

I am just letting ideas fly here. I would definitely start with these as mains and if you wanted to go smaller and/or less $ on the surrounds you will still end up with a very capable system.

I think I have room envy. tongue.gif
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post #16 of 47 Old 06-03-2013, 07:21 PM
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Thx Noah
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post #17 of 47 Old 06-03-2013, 07:37 PM - Thread Starter
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I appreciate all the input! What would be the advantage to the sentinels for surrounds aside from timbre matching? Would you expect enough low frequency content in the surround mix to warrant a 15" driver?

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post #18 of 47 Old 06-03-2013, 08:05 PM
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In short yes and yes. Having the ability to tackle whatever come their way. Headroom is never a bad thing if their is budget available to do so. When that transformer gets thrown off screen left or the helicopter travels over your head, I would choose to retain as much capability in reproducing the same content as it makes this transition. If I had the space and budget to add this level of continuity, I would do it.

Others here may have other input.

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post #19 of 47 Old 06-04-2013, 06:50 AM - Thread Starter
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I was under the impression that the surrounds were limited bandwidth channels. I Googled it, and nope, full bandwidth. I'm not sure where I got that idea from.

Good info. I think $400 per surround channel will stretch my budget for 6 surrounds (I'm actually doing a side array with two speakers per channel), and require a column redesign. I'm not saying I won't do it, but I haven't seen many theaters with surround channels that size, so it's something I'd have to get comfortable with.

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post #20 of 47 Old 06-04-2013, 07:00 AM
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I support the idea for the Sentinel up front great preformance for $ spent

another great option is to go with the Celestion buyout design seen here http://www.diysoundgroup.com/forum/index.php?topic=221.0 definitely the cheapest option if the drivers are still available. they wont play as low as the Sentinels but with subs it should be a non issue

for surrounds if you are not space limited any of the 12" SEOS designs using either the 10" or 8" woofers will work. if you cant fit something that size the designs using the EOS-8 horn (alpha and fusion 8) will fit better. they wont be timbre matched to the LCR but i doubt you would notice it


i run the SEOS 12 Tempests up front and use the Delta 10 max as rears which also use the SEOS 12
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post #21 of 47 Old 06-04-2013, 07:16 AM
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Quote:
Originally Posted by J_P_A View Post

I was under the impression that the surrounds were limited bandwidth channels. I Googled it, and nope, full bandwidth. I'm not sure where I got that idea from.

Good info. I think $400 per surround channel will stretch my budget for 6 surrounds (I'm actually doing a side array with two speakers per channel), and require a column redesign. I'm not saying I won't do it, but I haven't seen many theaters with surround channels that size, so it's something I'd have to get comfortable with.

The majority of typical living rooms do not have the space to pull it off. I am in that camp as well. I am room limited to smallish surrounds and 5.1 although my Yamaha can do 7.1. One of my great friends is a sound engineer and I pick his brain every chance I can get. Most people wouldn't have any idea a component is limited because it sounds so much better than anything they are used to. In the end, if you are happy, that is all that matters. smile.gif
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post #22 of 47 Old 06-04-2013, 09:22 AM
 
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You could just do sentinels as LCR and then do the tempests as your 6 surrounds, that would save 600 bucks and you'd barely lose any output. I doubt you'd even have the 500Wpc on the surrounds that really make the sentinels better than the tempests.
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post #23 of 47 Old 06-04-2013, 11:54 AM
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Quote:
Originally Posted by Sibuna View Post

I support the idea for the Sentinel up front great preformance for $ spent

another great option is to go with the Celestion buyout design seen here http://www.diysoundgroup.com/forum/index.php?topic=221.0 definitely the cheapest option if the drivers are still available. they wont play as low as the Sentinels but with subs it should be a non issue

for surrounds if you are not space limited any of the 12" SEOS designs using either the 10" or 8" woofers will work. if you cant fit something that size the designs using the EOS-8 horn (alpha and fusion 8) will fit better. they wont be timbre matched to the LCR but i doubt you would notice it


i run the SEOS 12 Tempests up front and use the Delta 10 max as rears which also use the SEOS 12

I like the LCR Sentinel with budget Celetion rear surrounds. Really hard to beat for the price if you've got the room! Or save even more money with the Celestion's all around.
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post #24 of 47 Old 06-04-2013, 12:27 PM
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Quote:
Originally Posted by J_P_A View Post

I was planning for them to go behind an AT screen wall. I could do baffle wall, but I'm a little concerned about getting the placement just right since the baffle wall would lock me in on the location.

I'm open to suggestions on he placement! Also, I think I'll need to look at the smaller options for the surrounds. A cabinet for a 15" speaker will probably be pushing it for hiding it in a column. Suggestions there?

I understand your concern. I would likely go screen wall myself*, however baffle wall approach certainly brings inherent advantages. And yes, it would lock you in to positioning, but that's no problem. The ground up/blank slate style of your room lends itself to about anything you would want to do.

Flush mounted mains eliminate SBIR related FR peaks and dips generated off the front wall. Also, the departure from free standing, toward halfspace loading will increase the bottom end of the coverage range, this would need some measure of compensation. I'd suspect Audyssey or equivalent shaping would easily tame the additional fullness, but I've never used it that way (fwiw; Seaton has stated this is Audyssey's wheelhouse). Other benefits include no diffraction from cabinet, increasing imaging stability and FR smoothing.

Full baffle wall/flush mounted approach places some additional demands on rear wall acoustic treatments, especially for music. A bass managed multi-location sub system lessens this somewhat, however flush mounting up front typically excites all front-to-back modes. Also, flush mounting mains is exactly that...flush mounted. It's important they must be perfectly flush and even all around. Here's the rub as I see it; The design hallmark of these speakers is the wonderful manner in which they control directivity. Aggressive toe angles in set-up would not be uncommon w/the L&R. This is the only reason I'd be hesitant, because I'd experiment extensively with the coverage pattern and toe angle. This isn't conducive to the premise of the flush mounted approach.


Even though flush mounting is superior, some type of semi open screen-wall may be best. This would essentially allow all the placement changes you'd encounter. Plus, you could incorporate massive absorption/bass damping for very little expense (thick fluffy). You lose the extra SPL that the flush mounting gives you, but those bass managed mains should be fine.

Good luck



*I've got a modest, multi-use family room/media room for my HT. If I were building, given the space, I'd employ a quasi screen-wall approach on all walls. Somewhat of a faux wall, studs only, covered in fabric and trimmed in wood, so all treatments ... be it massive absorption, or diffusion/scattering, could easily be implemented with no visual component whatsoever. Thick bass damping all around, then layer on diffusion to taste, to retain MF/HF presence and air.

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post #25 of 47 Old 06-04-2013, 01:44 PM
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You can also build a pseudo baffle wall setup that isn't a permanent fixture and get all of the benefits without some of the negatives. The key is understanding which frequencies are effectively being contained by the said baffle wall. You basically just make the baffle of your speakers wide enough for the speaker to "see" a half or quarter space. Eliminating SBIR is the biggest advantage IMO.

More specifically I'm suggesting mounting the speakers to wider baffles that are themselves adequately braced. The speaker itself would be wholly contained in its normal enclosure size. Behind the baffles bass trapping can be present because the baffles don't need to seal off the room. You can also place subs in the corners of the room behind these wide baffles. The key is ensuring that for the expected frequencies produced, the baffle is always adequately large enough to keep everything "in front" of the baffle down to about the schroeder frequency.

Angling, positioning and even changing/upgrading speakers is still possible with this approach as opposed to a more permanent baffle wall. I know I'm not explaining it very well, but I will post some Sketchups of the concept when I get a chance.

Edit: I should add, that if feasible, incorporating FOH's approach to the rest of the room is a great idea. I kind of wish I had done that but it does take away floor space. It is very common in no expense spared studios though. It would also, IMO, require professional design and a large treatment budget. It would be very easy to go overboard on absorption which I think is a critical mistake.
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post #26 of 47 Old 06-04-2013, 04:31 PM
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Quote:
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More specifically I'm suggesting mounting the speakers to wider baffles that are themselves adequately braced. The speaker itself would be wholly contained in its normal enclosure size. ...The key is ensuring that for the expected frequencies produced, the baffle is always adequately large enough to keep everything "in front" of the baffle down to about the schroeder frequency.

Can you give us some estimates for frequencies and sizes here? I'm new to this entirely, but I think I understood that F3 for the BSC is calculated as 380/Width (in feet). That sounds to me that with an 18" (1.5') baffle, you're already down to schroeder, give or take. Am I misunderstanding or is F3 for BSC not relevant for this conversation? I would have thought that I'd want half-space all the way down to my sub XO.

Edit: I see after a few minutes of thinking that Schroeder is the reasonable target, but I thought I'd seen recommendations from the likes of Dennis Erskine for five foot baffles.

Sorry to further derail this from finding J_P_A some speakers.
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post #27 of 47 Old 06-04-2013, 04:58 PM
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Quote:
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Noah, do those come with a crossover? Also what kind of enclosure do you use?

Missed this; enclosure is ~.5 cf ported, tuned to 85 Hz IIRC.

Nice thing about coax is you only have to cut one hole and gives a small faceprint (did I just coin a new term?)

Also has uniform radiation pattern with circular symmetry which helps when listeners are close to the surrounds, as they often are

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post #28 of 47 Old 06-05-2013, 07:38 AM - Thread Starter
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This is interesting stuff. I certainly don't question the efficacy of a baffle wall. Particularly for speakers designed for them. However, as mentioned earlier, my concern really boils down to speaker placement, an not necessarily just the LCR. I'm planning subs that will need a lot of real estate, and it would be nice to be able to move those around a bit to minimize modal issues. I like the idea of a "partial" baffle, but it would seem to go against the baffle wall mantra of build it 2.... no..... 3 times as solid as you think you need to. Doesn't the Procella paper recommend MDF followed by 2 more layers of 5/8" DW with something like Green Glue between each layer? That's serious, there!

Surround design is also in question. Since I'm considering a side array, should I go with more directive speakers or speakers with broader dispersion? I would think for a single set of surround channels (no side array), that a broad dispersion speaker would be the default. Once you add the array, I'm not sure anymore.

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post #29 of 47 Old 06-05-2013, 08:47 AM
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Did you use the B&C crossover? Seems like they don't offer crossovers for their newer coaxial drivers, but it has been a while since I've looked.
Quote:
Originally Posted by noah katz View Post

Missed this; enclosure is ~.5 cf ported, tuned to 85 Hz IIRC.

Nice thing about coax is you only have to cut one hole and gives a small faceprint (did I just coin a new term?)

Also has uniform radiation pattern with circular symmetry which helps when listeners are close to the surrounds, as they often are

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post #30 of 47 Old 06-05-2013, 09:56 AM
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Quote:
Originally Posted by HopefulFred View Post

Can you give us some estimates for frequencies and sizes here? I'm new to this entirely, but I think I understood that F3 for the BSC is calculated as 380/Width (in feet). That sounds to me that with an 18" (1.5') baffle, you're already down to schroeder, give or take. Am I misunderstanding or is F3 for BSC not relevant for this conversation? I would have thought that I'd want half-space all the way down to my sub XO.

Edit: I see after a few minutes of thinking that Schroeder is the reasonable target, but I thought I'd seen recommendations from the likes of Dennis Erskine for five foot baffles.

Sorry to further derail this from finding J_P_A some speakers.

This is basically about directivity control of frequencies above Schroeder where the room becomes modal. Let's assume that is around 188hz. A 188hz wave is 6ft long. To fully "contain" this the baffle needs to be 6ft wide. Erskine's 5ft is probably adequate in reality. That would need to effectively be a 5ft diameter. As you approach the side walls the baffle doesn't need to be quite as wide as the walls themselves will act as baffles constraining to tighter than 180 deg.

BSC is the -3db point in theory. BSC in reality doesn't work quite that simply. It is more of a ripple and becomes more complex depending on what is behind and near the baffle. The idea behind the baffle wall is that you are trying to keep everything in front of the speaker. With an 18" wide baffle, only a wave smaller than 750hz is fully contained.

Anyway, here are some sims of different baffles:



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You can see how much better the wide baffle looks. You can also see how the low corner shifts when going from the 5' baffle to the 7' baffle. Keep in mind that this is a sim and the actual environment is more complex and generally less exagerrated (the cone is not a flat piston, there are inevitably other boundaries nearby like floor, ceiling, side walls). The wide swings around

Concerning how it is built, the keys are for it to not vibrate and for it to not create a resonant or pressurized chamber behind it. There are ways to do this. Also keep in mind that if it is not sealed off well the walls behind it will still be functional acoustically at lower frequencies. You basically want to go full on build it like a tank and seal it off, or the opposite. The purpose of the baffles I'm describing is to contain sound above about 200hz. You still have to handle the modal region as though the baffle isn't working in that way. It really isn't a "wall" because it isn't sealed. It is just a giant flat baffle. If you build an actual sealed wall, it does need to be strong because it will act as a diaphragm if you don't. The same goes for any wall though.
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Klipsch Synergy F 20 Premium Dual 6 5 Inch Floor Standing Speaker

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