I want a sub, but I don't want the BIG box

Ron-P

After the few responses in my IB thread, it's not for me. Cost is a biggie, I don't want to have to buy several more drivers and so on.

I'm currently running a single 15" Tempest in a ported box with 2-17" flared ports, she's tuned to below 20hz. The box is roughly 4'x2'x14" and it's now too big for my redesigned room. It used to be under the futon in the back row, completely hidden.

So here's my thought. The back of the room had a whole cut in it for a AC unit I used to have in there years ago. I was thinking of opening that back up and mounting the sub box to the outside of the theater wall leaving the opening just big enough for the driver to come through. This should still give me the same amount of bass without the big box inside the room...thoughts?

everpress

Ron-P wrote: »

After the few responses in my IB thread, it's not for me. Cost is a biggie, I don't want to have to buy several more drivers and so on.

I'm currently running a single 15" Tempest in a ported box with 2-17" flared ports, she's tuned to below 20hz. The box is roughly 4'x2'x14" and it's now too big for my redesigned room. It used to be under the futon in the back row, completely hidden.

So here's my thought. The back of the room had a whole cut in it for a AC unit I used to have in there years ago. I was thinking of opening that back up and mounting the sub box to the outside of the theater wall leaving the opening just big enough for the driver to come through. This should still give me the same amount of bass without the big box inside the room...thoughts?

So the A$$-end of your sub will be outside the house? I mean, covered and protected from the elements and animals... But outside the house?

I am so glad I don't live around you.

Systems

Keep in mind the ports would have to fire into the room aswell.

megasat16

I thought about doing Quad IB Array a while back. IB array needs to mount physically in a separate room such as behind walls or in the attic. Then you need to have the mouth opening into the HT room.

Acoustics Elegance (AEspeakers.com) have some nice IB subs. I also heard a lot of good things about Mach 5 IXL subs, FI IB18 and ED 19OV2 as IB subs.

http://www.mach5audio.com/zen/index.php?main_page=product_info&cPath=65&products_id=181

Here is the thread I started on HTS but not really built it due to space limitations in my attic.

http://www.hometheatershack.com/forums/diy-subwoofers-infinite-baffle/15131-help-me-create-ib-array-4-x-fi-ib18-4-x-ed-19ov2-18-8-x-ae-ib15.html

megasat16

Ron-P wrote: »

The back of the room had a whole cut in it for a AC unit I used to have in there years ago. I was thinking of opening that back up and mounting the sub box to the outside of the theater wall leaving the opening just big enough for the driver to come through. This should still give me the same amount of bass without the big box inside the room...thoughts?

I think for IB to works correctly, the back of the room needs to be some kind of acoustic suspension (i.e. room of some sort and not free air). You need to have the correct size opening from the IB into the room as well.

There are a lot of info in DIY IB subs. I've learn that people using Chimney to mount IB array is actually doing Transmission Line and not IB.

tryrrthg

GV#27 wrote: »

Keep in mind the ports would have to fire into the room aswell.

What he said, which means your box would have to be probably 20 inches deep to accommodate your ports. You could use elbows but I think that can get ugly when doing port length/area calculations...

You could also go with a sealed sub. You would give up some low end extension and SPL. I'm guessing your room isn't very big so room gain would probably make up for the loss of both.

ShinAce

Tempest is a 'big time' vented driver. I would not go sealed unless reduced output is fashionable.

Can we get more info on the AC cutout?

madmax

Ron-P wrote: »

...thoughts?

I have considered this idea as well, but didn't do it. I see no problem other than sound getting out to your neighbors. I'd build a box in a box to eliminate that problem. Keep in mind that you could have something like a dual bandpass (which only has ports as the output) and only have two port openings to the room, not the whole driver. Probably doesn't matter in your application but the port only idea allows you to place the sub anywhere so long as the port length is long enough.

Face

Big bass out of a small box: http://www.madisound.com/catalog/product_info.php?cPath=45_338_340&products_id=8535

I'd have to model it again, but IIRC, in a sealed 1ft3 box and a plate amp with bass boost, you should have nice flat response to around 20hz. I've been thinking about building a pair of these for my HT setup for a few months now, but I've been too involved in other projects.

everpress

ShinAce wrote: »

Tempest is a 'big time' vented driver. I would not go sealed unless reduced output is fashionable.

Can we get more info on the AC cutout?

I wonder if you could build the box to go outside, and elbow the vents to come back in? If you soundproof the box, maybe the neighbors won't notice...

ShinAce

everpress wrote: »

I wonder if you could build the box to go outside, and elbow the vents to come back in? If you soundproof the box, maybe the neighbors won't notice...

For a bandpass box, sure, since all the output is from the vent.

For this ported box scenario, both the surface of the speaker and the opening of the port need to be in the room.

p.s. the vent itself can exist anywhere, as long as one end is in the box and the other is outside the box.

Ron-P

everpress wrote: »

So the A$$-end of your sub will be outside the house? I mean, covered and protected from the elements and animals... But outside the house?

I am so glad I don't live around you.

No, my theater is a room within the garage, the sub box while outside the theater would still be inside the garage. The neighbors wouldn't be bothered.

My test today will be setting up the sub outside the theater, yet right up against the wall, basically mounted right to the exterior wall of the HT. This will give me an idea of what it will be like while inside the theater and then also inside the garage.

I can always mount the sub box to the HT wall and move the ports so they fire into the room along with the driver yet not changing the dynamics of the setup.

madmax

Using the clark synthesis transducers on a platform under the seating might be a logical alternative to a subwoofer. I just mounted mine over the weekend and they kill any sub I've had.

Ron-P

Yeah, I was thinking of buying a couple of Aura Pro's to throw under the seating.

madmax

They aren't too bad, but they are not Clarks by any means. They are more of a mass vibration than a real sub. Still fun. The Clarks are accurate from 5 hz to 15khz or so. Not that you would want to but you can feel even the upper midrange if not crossed over properly. They do have one around $100, their lowest model which I would suggest when the time comes. I wish you were close enough to stop by and hear what they do. For whatever reason you think you are hearing them when really it is just tactile. I'll post a thread on mine once I take some pics.

Did you add AC from the house to the theater?

Ron-P

Parts Express has the Clark TST209 for about $80, almost twice the price of the Aura, but, if they are that much better then I'll wait and save more fun funds to get those. Plus at this point I'm going to try my best to make my Tempest work with my new set up.

As for the AC. I cut a hole into the center, lower part of the theater at the garage door end (where the screen used to be) and I had a small window AC unit in there. But, since I bettered the air flow in the room it was not need so I closed it up. The hole is easy to reopen and is roughly 18" by 24".

Ron-P

I am jazzed.

I just did some quick measurements and the existing sub, with a little modding to one side will fit right behind the rear seating. I had more room back there then I thought.

I loved when it was directly under the futon because I had it turned really low and the cut off real low and it was perfect. Hopefully, having right behind the seating will yield the same results.

mantis

Ron,
your room needs room not another sub or sub box in the room. I strongly suggest you check out these subs. I Install them all the time with killer results.
http://www.paradigm.com/en/reference/in_wall_in_ceiling-rvc-series-2-6-25.paradigm

Follow that link and also get the back box. It makes a huge difference. I never ever heard a in wall sub perform like this one does. Do yourself a favor and just buy it. It's that damn good. I'm not a huge Paradigm fan but there in wall sub is unbelievable.

Another really good in wall sub maybe not quite as good as the Paradigm but damn close. I actually think if Def Tech built a full size in wall box ,they could surpass the Paradigm, they would also need room correction software. But check it out man, I think you would like a nice pair of these bad boys in the wall.

http://www.definitivetech.com/Products/products.aspx?path=Subwoofers&productid=IWSub%20Reference

This is the right choice for that room. You have exposed exterior wall so cutting these woofers would be fairly easy. The Def Tech sub has it's back box built on the speaker. The Paradigm you have to Install. It will require some drywall repair but dude it is well worth the project. you seem handy being you built the room.

If you have any questions, let me know.

hoosier21

Dan,

What part of

Ron-P wrote: »

Cost is a biggie

leads you to think he wants to buy a 1K subwoofer and matching 2k amp? (paradigm option)

or the 1200 dollar Def Tech :rolleyes:


these may not be your real recommendations as you did not title your reply "Official"

Ron-P

Yeah, I'm trying not to spend any money, or very minimal on this project. My backyard project kinda shot my fun money budget for the next several months so those aren't really something I'd consider at this time.

The sub box has been deconstructed, cut down and rebuilt. Next up is some new polyfill and then to seal it up. Hopefully have it in-place and up and running in a few days.

Systems

Ron-P wrote: »

The sub box has been deconstructed, cut down and rebuilt. Next up is some new polyfill and then to seal it up. Hopefully have it in-place and up and running in a few days.

So you will now be using that same 15" driver in a small sealed box?If so your output below 30hz will be substantally reduced.

Ron-P

No, it's still ported with the duel 17" ports. Once I do some final calcs I may reduce the port lengths but I'm not sure yet.

Ron-P

The sub is done, in place and the rig is auto calibrating right now via my Onkyo. I ran AVIA and I was getting base down to 20Hz with no roll off and no rattles in the theater. Had a small dip at about 54Hz but nothing to be concerned with.

I had to shrink the box by about 2 cf so I plugged one of the ports and the results were outstanding. Having both ports open, the base was too flat and lifeless. Smaller box = less porting.

ShinAce

Ron-P wrote: »

I had to shrink the box by about 2 cf so I plugged one of the ports and the results were outstanding. Having both ports open, the base was too flat and lifeless. Smaller box = less porting.

Smaller box = less porting? What does that mean?

megasat16

If you plug a port, bass would be tighter at the expense of lesser output. For SQ, a sealed sub is a prefer choice for some of us.

Ron-P

I though about going sealed but it's not recommended for the Tempest driver. Plus I would have had to build a completely new box. I was able to just do mods to this one to get it where I needed.

As for lesser output, I'm running the amp at about 1/4 volume and it's plenty powerful, of course I do have a small dedicated HT room so I don't need lots of power to get excellent results, and the sub is directly behind the seating area so it works perfectly.

Grimster74

Okay Ron, so where are the pics buddy?:D

ben62670

Glad to hear that you are pleased. Time to bust out the popcorn!

mmadden28

Ron-P wrote: »

Parts Express has the Clark TST209 for about $80, almost twice the price of the Aura, but, if they are that much better then I'll wait and save more fun funds to get those. Plus at this point I'm going to try my best to make my Tempest work with my new set up.

...

FYI, PE has the TST209 on sale thru 10/18 for $66--I think I'm going to try one out.

madmax

mmadden28 wrote: »

FYI, PE has the TST209 on sale thru 10/18 for $66--I think I'm going to try one out.

Oh man, what a deal! I may pick up a few for in my couch and chair.
madmax

madmax

I didn't buy any of the clarks on sale for the couch or chair but I did get some older ones installed in the ceiling of the basement. My couch is above it. These are the 329's which are more powerful than the ones on sale. I'm driving them with a 500W mono sub amp. On most stuff they add drama. On rap music and stuff with a lot of bass they absolutely shake the crap out of you. You can even see the cushions vibrating... Lots of fun! I used to have 4 of these on the main beam of my old house and they shook the whole livingroom. The current setup shakes an area about 8' x 18' centered on the two joists they are attached to.
madmax