THIN sub questions- just getting started. - AVS Forum
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post #1 of 6 Old 04-10-2013, 11:56 AM - Thread Starter
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Hi, all. I have a horrible room, totally open floorplan. The room is a rectangle that comprises living/dining, 15x30 with a 25' cathedral ceiling and exposed beams. One of the long walls is essentially not there, open to the rest of the house. Looks great, sounds awful. The plan is to use remote speakers in LOTS of locations. Right now, for starters, I have the TV and two MK satellites in one of the 15' walls. Using the old MK 12" sub in the corner. For reasons I cannot really explain, the sub isn't gonna work. The sofa is placed about 15' off of the wall with the TV, and I HAVE to put the sub under it. So it's time to build. Max Dimensions are 120" long, 30" wide, and 6" high.

I have both power and an open conduit going under the slab from where the gear sits to under the sofa. I can get wire to the overhead beams, but there is NO ceiling plenum. So, it's satellites on the beams, sub under the sofa time. Building a "furniture sub" is not an option. We have the furniture we like.

Any suggestions as to what to put under there??? I've seen the "boogieman" but really question 4x8". Not sure why, maybe it's OK. On the other hand, there are a LOT of thin caraudio subs, but I'm not sure how that would work out. I'd be powering it, not passive, so can define the amp as needed.

Thanks for any input...

Stephen.
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post #2 of 6 Old 04-10-2013, 07:46 PM
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4 of these?

http://www.parts-express.com/pe/showdetl.cfm?partnumber=265-374

Given your size limitations this would be a place to start. Add a plate amp for simplicity...http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-807

No clue what budget you are working with but that should shake your butt for $500.

What's your budget and what does the rest of the system look like?

If you can cheat and raise the sofa ~2-3" by putting the feet up on little risers you blow open your choice of drivers. Try that first to see if it is acceptable.
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post #3 of 6 Old 04-11-2013, 01:18 PM
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Thoughts start with the Boogieman.

The TB driver is a monster for its size, and fortunately, it comes in both neodimium and ferrite versions, at a nearly 2x price delta. My take is they're interchangable, and my simulations agree.
http://www.parts-express.com/pe/showdetl.cfm?partnumber=264-919
http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=264-832

Mobeer suggested a low-profile 12" with modest Xmax befitting a car audio application. I will note the absence of an Sd (cone area) spec in their literature, so I suspect this 12" radiates like a much smaller driver. Still, Sd of a 12 is ~500 sq cm compared with 140 sq cm for the TB W6, which makes 4x used in Boogieman equivalent or better. Where the BOSS driver shines is sensitivity, it has a 12 dB advantage over the little TBs, and they only make up half of that with 4 drivers. Conversely, the TBs have over 2x the excursion capability, so there's likely a Hoffman's Iron Law tradeoff here - size, extension, sensitivity, pick 2.

I already had a W6-1139 simulation, so I looked at the boogieman configuration. I think his write-up is off on box size; I don't like the result at anything less than 2 cu ft., but I like the response options you get when tuning the box to 30-40Hz.
- 30Hz maximizes extension and with room gain, overall flatness of response with an F10 of ~23Hz. 2 port of 4" diiameter about 32" long
- 35Hz is quite flat anechoically, so you hear all the room gain, has an F10 of 25Hz, and is achieved with dual 4" ports of 24" length.
- 40Hz provides a nice thump at 45Hz due to a 1.75dB peak, but the dual 4" ports are now only 16" long and F10 is more like 30Hz.

This is with Darren's 30" port, a 31Hz Fb, and clearly an "extended bass shelf" alignment (Fb <= F3 with a downward tilt).


I'll also note that I did a quick simulation of the BOSS and it's a strange beast. In 1 cu ft sealed, I'm getting F3 of 47Hz, vs. their 45Hz, so we're close, but 100W will exceed Xmax and Qtc is greater than 1, so there's a big bump in output at 70Hz per BOSS and 85hz per Unibox sims. This isn't what I want in residential HT. Plus at 100W, you're not making 110dB while the Boogieman will do 116dB with a 500W amp, and still has excursion to spare. I will note the TB are only rated for 50w, 100W peak, so don't expect to run sine waves at this SPL, but for music and HT, you want amp headroom. Conversely, 500W is only 2dB louder than 300W...

Hope this makes sense...

Have fun,
Frank
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post #4 of 6 Old 04-12-2013, 10:04 AM
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post #5 of 6 Old 04-15-2013, 11:11 AM
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Quote:
Originally Posted by djkest View Post

What about 2-4 of those Anarchy tapped horns?
Quote:
Originally Posted by s clemente View Post

...Max Dimensions are 120" long, 30" wide, and 6" high (emphasis added, ed.). ....
Anarchy TH are 8.25" wide, and there's no getting it smaller - doesn't fit the OP's space liimitations. The Anarchy driver is a mid; Fs of 45Hz is too high to compete with something like W6-1139.

If he had 8.25" this would be high on the list. A very good sub, but not particularly small. However, 6 would fit in 120" x 30"... and 4 would make a very nice solution with plenty of headroom. Horn subs have some very nice properties...

HAve fun,
Frank
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post #6 of 6 Old 04-15-2013, 01:22 PM
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Build a riser that is much bigger than the footprint of the couch and use the riser as a sub enclosure?

YID DIY
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