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post #1 of 14 Old 12-24-2018, 09:21 AM - Thread Starter
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Suggestions for theater sub type

Open to suggestions for what to do with the area set aside for subs in front corners of theater. See attached concept sketch. This is a work in progress, trying to sort out just how to handle the rear with lobby, equipment, restroom.

But also interested in suggestions for main subs up front. Have plenty of space to work with, around 400 cu ft or so on each side. I've always assumed I would build these into the room after isolated subfloor and walls are in, ie stud framing and a couple of layers of osb or ply sheathing.



Always been a fan of IB for quality, ease of integration etc. For a starting point, I'd be happy putting perhaps 8 UM 18 or IB3 18 per side. From a budget perspective, its tempting to look at more PA460 drivers, like 12+ per side, as it increases cone area and all the good stuff that goes with that even if displacement and ultimate single digit output suffers.

Never been a huge fan of horns, mostly because of the build and integration complexity. But certainly have room for a couple of large ones. Or SLLT ported enclosures. I know notnyt went that direction and doesn't seem to regret porting.

So I could be talked into pretty much anything. Just don't see the need in spending money on super high end drivers since I have room for plenty. eg, no reason I can see to stick a few SHS24 on each side other than cool factor.

Also, worth mentioning that side walls and ceiling will be fabric with sound treatments behind. There would be room on the sides for a couple of smaller sealed or ported enclosures to help smooth response. I'm also strongly considering a couple of nearfield enclosures in front edge of riser that fire into back of front row and possibly at foot of rear row if dual opposed. Hard to ignore the craze of nearfield subs, and if nothing else would help in further smoothing total response.

Ideas and suggestions?
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post #2 of 14 Old 12-24-2018, 09:33 AM
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I don't know exactly what you budget is here but from the looks of things i would say go for some of the SI IB-24's twice the cone area and more Xmax. If it were me i think that is the route i would go. You have to talk to nick as they are not on the site but he will still custom build them for you. Otherwise the Re XXX 18 would be another possibility. I know @MKtheater uses them with great results.
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post #3 of 14 Old 12-24-2018, 09:47 AM - Thread Starter
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Budget isn't set but I don't want to spend money unnecessarily on sub system when there are plenty of other parts of the system that will need the funds.

Also, with room to comfortably fit several dozen sub drivers if needed, uber subs seem a little wasteful and overkill.

Its all a matter of perspective I guess. $5k on drivers and UM18's are unnecessary, overkill, uber subs, and wasteful to plenty of people!

I guess the real question isn't about getting every possible ounce of performance out of the space I have available, since I have plenty of space. Rather, what approach would you take to put that space to use to getting stunning sub performance at a value.
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post #4 of 14 Old 12-24-2018, 10:00 AM
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Nothing sounds as good as the IB subs I have in the room. Of course this is with a LT engaged to compete with the SLLT. I prefer two uber drivers to 8 good drivers as ULF is concerned. If you are going with IB excursion is key, I would get the xxx18, Si 24, or Fi car IB3-18 v2. You have plenty of cubes for them. The FIs require the most room. The low end added to the bass always seem to make it more realistic to me and every time I switched and tried a higher tune ported or horn it sound thin to me but with great mid bass. The DTS-10s I had closed the gap but they needed EQ to sound good, lots of it. The IB has always been smooth in my room. Just makes sure you know where your best response is from locations up front and put the drivers there.

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post #5 of 14 Old 12-24-2018, 10:29 AM - Thread Starter
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Interesting. I have had many types of subs over the years except IB - was always on the drawing board but never the room to implement.

I thought displacement was displacement when it came to IB. Do you really feel there is a qualitative difference in sound when say 10L displacement is coming from 2 subs instead of 6?

Spreading it out has advantages in power compression, probably power required to drive, one would hope suspension noise, and depending on quality of comparative motors perhaps motor distortion too. But I don't want to overlook something because of my assumptions.

I've thought about the measuring aspect. I'm not going to have my room CFM/FEA modeled or anything. If I build IB or some huge structural ported enclosure, location will probably be fixed except for perhaps exact driver mounting position.

What I can change is position of "helper" subs around the room and in riser, and of course response tailoring of all of them based on in room measurements.

That coupled with copious broad band absorption (not covering every surface or anything, but I'll have room for some dedicated sub absorption measuring a few feet thick) seems a reasonable risk to take.
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post #6 of 14 Old 12-24-2018, 11:13 AM
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Nice room layout.
I would put the speakers closer to the dotted red line and go with a bigger screen. It would make the 2nd row and bar area sound better, in particular.

The projector, the center channel and the subwoofers are the 3 most important aspects of a home theater. Those are the LAST places you want to short yourself.
The rest is just cosmetics and nice-to-have's...

8 to 32 FI-IB's would work well. Trust the Box-model... (Whatever Box-models best for the space/money.)

If cash flow for the subs is tight, I'd leave that to the very end. You can always save for another 6-12 months and get your dream-subs.
If you are doing it as part of a loan/mortgage, then I'd get what-you-can\while-you-can.

If I were you, I'd look at doing 3 speakers behind the screen, in addition to the L/R you have blueprinted already.
Those 3 would be the LCR during movie-mode, and the existing L/R you have mapped would be for music-mode only. The tonality between the center channel and all of your other speakers will differ substantially because of that AT screen; at least that way the LCR maintains a consistent tonality. and in music-mode the sound remains unimpeded. If you will never do music, then just put the LR behind the screen. Something to think about anyways...
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post #7 of 14 Old 12-24-2018, 12:17 PM
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Quote:
Originally Posted by BassThatHz View Post
If I were you, I'd look at doing 3 speakers behind the screen, in addition to the L/R you have blueprinted already.
Those 3 would be the LCR during movie-mode, and the existing L/R you have mapped would be for music-mode only. The tonality between the center channel and all of your other speakers will differ substantially because of that AT screen; at least that way the LCR maintains a consistent tonality. and in music-mode the sound remains unimpeded. If you will never do music, then just put the LR behind the screen. Something to think about anyways...
For what it's worth, with my DIY spandex screen, I can't tell the difference if the speaker is behind the screen or beside it. My ears are also far from perfect. I know there are technically small frequency response differences when put behind an AT screen, but I've always seen them to be extremely minor. One of these days I'll bust out the UMIK and compare one of the speakers behind the screen vs slightly beside it.

Instead of adding a pair speaker, I would just move your L/R speakers in a bit closer and behind the screen, if possible. Dolby recommends 22-30 degrees off center for each of them, so that would bring you closer to dolby specs, anyhow. If you get it just right, you maybe around 22 for the front row and 30 for the rear... Or just pick which row you prefer and set that one around 26 degrees


Room layout looks solid to me. Nice work.

As far as the original topic, I think you'll be fine with whatever you chose. When going with IB or sealed vs ported/horn, it always seems to come down to how much or how many amps you feel like dealing with in exchange for those few single digit dBs. Personally, I vote for a couple big 'ol LLT ported enclosures, and then as you said, a few helper subs scattered around after you learn the room a bit. No real good argument as to why - I have no experience with horns, but they seem harder to integrate smoothly (and build) and you get the nice efficiency boost when using a ported sub. Just my vote in the matter.

Enjoy =)
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post #8 of 14 Old 12-24-2018, 03:04 PM - Thread Starter
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Nice room layout.
I would put the speakers closer to the dotted red line and go with a bigger screen. It would make the 2nd row and bar area sound better, in particular.
Screen is at around 55 deg horizontal width in that sketch. If I made it bigger and moved it back to keep viewing angle constant that would improve size from second row. Not sure it would necessarily sound better other than LR separation increasing a bit.

But current plans are for dipoles. Need the room behind them for optimum performance, which drives much of this layout. Could maybe be talked into a different speaker type, not because of sound, but maybe to eliminate the substantial construction effort I'm looking at.

Quote:
8 to 32 FI-IB's would work well.
Yeah I think my default is 16 IB3's. I'm good with that budget. But was interested in hearing other suggestions and checking my thinking.

Quote:
If I were you, I'd look at doing 3 speakers behind the screen, in addition to the L/R you have blueprinted already.
Those 3 would be the LCR during movie-mode, and the existing L/R you have mapped would be for music-mode only. The tonality between the center channel and all of your other speakers will differ substantially because of that AT screen; at least that way the LCR maintains a consistent tonality. and in music-mode the sound remains unimpeded. If you will never do music, then just put the LR behind the screen. Something to think about anyways...
Definitely a lot of music in this room, which is why dipoles, and again drives a lot of my thinking. Don't think I'd want to narrow the 60 deg separation. Never been a purist on the speakers behind screen thing. I may well add matching cloth over L/R for aesthetics and reflection control, which would remove any small gap EQ couldn't close. At least that's my thinking.
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post #9 of 14 Old 12-25-2018, 07:55 AM
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I cant stress enough how important room treatment is to get optimum surround sound and great bass.

As important as a type of speaker may appear... it is the placement and treatment of that placement that gives you the remarkable effects you seek, not so much the speaker itself.

I could comment on sub setup -- 2cents is IB low and a pa460 in 6 or 8 locations for 40 and up -- but room is not just important but imo 80%.

More absorption... if a theater... than most people consider...creates the dream that everybody wants. Overcome room issues and minimize limitations for best theater.

The layout schematic is really well done. Great job asking first before shooting. 🤴
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post #10 of 14 Old 12-25-2018, 09:41 AM
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Room layout looks great I am gonna save that image One advantage of uber drivers is less cabinetry and labor expense, and flexibility to move them a bit. You could do some massive absorption in that space as well. Also depending on the mains, consider that a combination of ulf focused drivers for <50 hz and some pro type drivers for the midbass -could give more impact possibly at the expense of integration complexity. Being a big hs24 fan I would consider one on each side and some 18 or 21 for midbass and then add near field. The ib24 is a great suggestion if you want to build them in, two on each side to cancel the force, but leaves less room for absorption.

Smaller subs that can be moved will give you more flexibility in placement to help get the best response in the room.

Is near field or tactile in the plan? Put a sub in the riser under each seat? Maybe just the front row? Tactile adds so much impact, it’s one of those things that takes the experience to the next level. Or motion actuators but it seems like more subs would help response at the multiple locations.

I think the surrounds could be direct radiating and still sound amazing. Having all the speakers on a circle around mlp has got to be the most enveloping surround you’re going to get. That doesn’t help the layout get simpler


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post #11 of 14 Old 12-25-2018, 11:02 AM - Thread Starter
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Originally Posted by RoboAVS View Post
I cant stress enough how important room treatment is to get optimum surround sound and great bass...

The layout schematic is really well done. Great job asking first before shooting. 🤴
Thanks! Still a work in progress. Will break ground first of the year so still have time to evolve and refine things.

Will definitely stuff in as much absorption as I can. Early sketches had very low frequency diffusion as well... QRD in rear would have been 4 feet deep... but alas final room while large just didn't leave that much extra space. Will be able to place absorption in ceiling down centerline, above soffits, behind fabric side walls up to a few feet thick.
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post #12 of 14 Old 12-25-2018, 11:07 AM - Thread Starter
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Originally Posted by Vince_B View Post
Room layout looks great I am gonna save that image One advantage of uber drivers is less cabinetry and labor expense, and flexibility to move them a bit...

Smaller subs that can be moved will give you more flexibility in placement to help get the best response in the room.
I guess portability is an option depending on final design. If I do sealed the cabs would be dozens of cu ft each. SLLT could be 10+ cu ft. May be easier to just build the front enclosures in place. But I do think smaller sealed or ported down the sides where I could play with exact positioning makes sense.

Quote:
Is near field or tactile in the plan? Put a sub in the riser under each seat? Maybe just the front row? Tactile adds so much impact, it’s one of those things that takes the experience to the next level.
Yeah strongly considering a few nearfield built into the riser front edge.

Quote:
I think the surrounds could be direct radiating and still sound amazing. Having all the speakers on a circle around mlp has got to be the most enveloping surround you’re going to get. That doesn’t help the layout get simpler
Current plan is dipoles all around. Not typical surround type dipoles, but something more like Linkwitz Orion's on theater steroids. So still direct radiating.

Midbass in each main likely 4 x 12's, at least up front. We will see.
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post #13 of 14 Old 12-25-2018, 12:18 PM
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Youve got the room, go for the LLTs. Extension to single digits along with more ouput, lower distortion, and better driver protection than the IB.
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post #14 of 14 Old 12-25-2018, 12:22 PM - Thread Starter
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Guess I need to model a few drivers in the space I have. The UM22 obviously has plenty of motor strength for it. Wonder if the Fi IB3 does.
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