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Lone 15" LLT or Dual 12" Sonotubes: chime-in!

15190 Views 77 Replies 11 Participants Last post by  ironglen
Need help with decision to build either lone 15" LLT box or dual 12" sonotubes. Looking at using a CSS SDx15/Acoustic Elegance AV15-x, or dual shiva 12"s. Primarily for deep content on HT as 'resonable' spl levels. Amp would be a Behringer 2500. Finances and space dictate no dual 15"s. The WAF is ok :kiss: (actually LIKES the cs12 I have now)

I bought an svs cs12 thinking it would be plenty of support as I use a 5.1 system with 80-150w rated in-ceiling/wall speakers with an onkyo 806, and it usually sounds good, but at 1/2 gain I don’t have any of the wall-shaking/window rattling experiences that other people at HTS have posted, not even close.

Can you help me given the space described below? :dumbcrazy:

To start, I have a living room HT upstairs ~16x16x8, that has 3 doorways to adjacent rooms, an open stairway in the front going down that has a landing near the left front of the room, and finally, one 12x8' right side (where a wall would be) that is open to downstairs with only a railing. Downstairs is ~14x35 and one end is open to this upstairs living room area with the HT(~25’ ceiling). After seeing what other posters have in the way of rooms, mine appears to very challenging in producing low reinforcement that they describe.
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I don't have access to a modeling program at the moment but I'd say 2 12's will out perform a single 15.
Also, placement will be much more flexible, and potential gains in sound quality because of dual subs.
Here is link to an article that discusses in detail the benefits of using multiple subs to help lesson room nodes.

Matt
Thanks for the feedback!

I was afraid that the 12" would not go low enough and maybe needed a 15", but I guess proper tuning will probably afford the low-end range, and the twin drivers will provide the needed headroom currently lacking. On the flip side, the twin drivers will have less distortion at an equal spl, correct?

I saw a post that stated a Behringer component could handle HPFing, but another stated contrary. If one of Behringer's or another will handle it, can someone tell me which one? I'd like to keep # of components to minimum, but a reckhorn or something else could be used- only I'd have to add an EQ component later:spend:d I guess a budget for a combo HPF/EQ of ~$250 would be equally cost effective vs buying two separately, any suggestions?

I'm reading that link on multiple drivers now- thanks Matt.

I guess the question will become which driver? The CSS and Exodus are the standouts in the sub $200/driver price range (my budget), and according to other threads I have read, but perhaps...there...is... another... (yea, I like starwars :yes:)
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How about a single 18"?
Uh, never considered it-should I? Haven't even looked at the needed box displacement. The space(s) I have available are probably not conducive to an 18" and we won't live in the current space for more than a year or two...unless...I could conceive an idea for a closet-based enclosure with a port into the living space:scratchhead: I'll have to think on that, and maybe take photos and see if perhaps someone can ingeniously incorporate one:devil:
If I am reading right, the HT is located in a bit of a loft that's open to the rest of the house? With the 16 x 16 x 8 dimentions you posted you might have one of a mode that will 'ring'. The dimentions are multiples of one another.

Can you modify the room size at all, and have you run REW to get a feel of what's going on in there?
If I am reading right, the HT is located in a bit of a loft that's open to the rest of the house? With the 16 x 16 x 8 dimentions you posted you might have one of a mode that will 'ring'. The dimentions are multiples of one another.

Can you modify the room size at all, and have you run REW to get a feel of what's going on in there?
Yeah, it's like a loft, but I'm not sure what you mean in the second statement. Other than closing the adjacent doors, no adjustment can be made to the room. I do not have a bfd yet. I was hoping to build subs and purchase amp, add some sort of hpf for protection and add eq a little later :spend: I can't incorporate a bfd without the other equipment first, correct? :ponder:
I would spend some time with room eq wizard to measure what you have at the moment, and see what you have for room gain before building subs. With about $ 150 in gear and a PC you already have and RoomEQ wizard you can take a bunch of measurements before you proceed with a subwoofer build. It will also help you identify the best placement for a subwoofer.

It can help you save money in the end, as you may find your sub needs are less than you anticipate. You can use a BFD and set filters manually, but it's easier if you use RoomEq wizard.
I would spend some time with room eq wizard to measure what you have at the moment, and see what you have for room gain before building subs. With about $ 150 in gear and a PC you already have and RoomEQ wizard you can take a bunch of measurements before you proceed with a subwoofer build. It will also help you identify the best placement for a subwoofer.

It can help you save money in the end, as you may find your sub needs are less than you anticipate. You can use a BFD and set filters manually, but it's easier if you use RoomEq wizard.
Sounds like that might be good advice:yes: What equipment would I need? A good mic?....

Looking at 18" builds, and even 15"'s, man that's a HEAVY piece of heaven. The weight is something I'd have trouble with, upstairs and moving in a year or two...I'm painting my 10" sonotube and it weighs a hefty, oh 45 lbs or so. Building is pretty easy, even with my weak/pathetic jig saw and busted router. Wife was surprised I created the endcaps as they looked nice, I guess. Looking like a couple Shiva's in 18" tubes may be about my only option, for now, but measurements sound like a good idea.
Also look at the Mach 5 18.2.2 subwoofers - good value and performance in my opinion....
Simplistically speaking, 2, 12's perform on par with a single 18 with equal amounts of excursion.
Having two subs can also help smooth the in-room frequency response.
Two subs can potentially smoothen response for more than one seating position, but it seems to me that it is easier to achieve a flat response at one seat with one subwoofer. Also, you'd better hope that you would be getting the full 6db gain with the second sub, otherwise they wouldn't stand up to an 18" with equal displacement capability.

I'd go for the single 18".
Thanks for all of the input guys:T Sounds like I would have a great setup either way, with adv/disadv to each. After perusing the site, I've seen substantial discounts, at times in the last year on various drivers-should I wait and see if something comes up?:dunno: Budget would currently be surpassed after adding a bfd, hpf, and the gear to run room eq wizard to the original subs, amp, and materials:spend:
As far as equipment needed, you can use a variety of products, if you have Vista there are less options for outboard sound cards though. I bought the Behringer ECM8000 mic, UCA-202 soundcard and Xenyx 802 mixer. Other items you will need is a 1/4" mono to RCA adapter, and a standard XLR cable with male and female ends, at least 10-15 feet long.

A long set of RCA cables can come in handy, I use a 20 ft set to connect to my AV receiver. You can read all about connecting the equipment and measuring in the REW forum on this site. You do need a calibration file for the mic or SPL meter, again available at this site.
Budget would currently be surpassed after adding a bfd, hpf, and the gear to run room eq wizard to the original subs, amp, and materials
Don't assume you need a BFD. Flat in room FR can be achieved a lot of the time by moving the sub and moving your seat around a bit. EQ should be the very last option, not the first option.

If you go with an 18" driver and a low tune, you won't need a highpass filter.


All you really need to get going is an amp and an spl meter.
If you go with an 18" driver and a low tune....
As long as the large cabinet size is acceptable.
As long as the large cabinet size is acceptable.
Steve, you're a true enthusiast (and pretty convincing too) :yes:

Has anyone posted on the forum a two-piece enclosure? :dumbcrazy: One that can be disassembled without destroying it and would be roughly half the weight each? A five hundred pounder is not moving into this house, closet or no, but a two-piece might!
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