Need help building a box sub to replace my sonosub

Ron-P

Currently I have a 177L 15" Tempest Sonosub (24" x 36") with 2-17" flared ports and is powered by a 250w PE.

Due to the up and coming redesign of the theater I cannot use this large sub. I need to build a box sub, more so, a rectangular one. The area it will go is under the rear futon. The area is roughly 6' long, 1' high and 3' deep. I'd like, if it's possible, to build a box to fit in this area and achieve the same base results.

Is it possible?

hoosier21

with only 1' depth, looks like it will have to be firing up , right? Can you do that, not sure

jdhdiggs

Instead of purely up firing, you could angle the front a bit to give you room for 2 12" and not have them firing directly up. You 15" may fit on that angle as well.

Also, depending on the depth of the 15" driver, you could offest 2 drivers if you did a top firing design. One mounted at the rear right, another at the front left.

This would leave no room for porting, but the volume is large so to plate amps would be enough..

These are some of my thoughts, use them at your own risk...

gatemplin

Hi Ron,

If there is enough clearance (about 3") between the futon and the base, you can mount the Tempest firing straight up and the ports on the end of the enclosure.

If there isn't enough space, you can build something like the crappy pic I made below. Either design would be about 16-18 cubic feet which would make this an EBS design and you would need to get 2 4" precision flared ports with full length tubes. Depending on the volume you would be tuned between 15 - 17 Hz. That is no problem for the Tempest, the bigger the box the better.

tryrrthg

It's possible you just have to make a box with the same internal volume as your current sub. You could do the math or just build a box that matches the internal volume of the Adire designs.

Adire Designs

PolkThug

A car audio shop can probably build what you need for not too much $.

Ron-P

I can build my own, that's not a problem at all. This is more along the lines of what I was planning to do if it worked out...

...make a box with the same internal volume as your current sub. You could do the math or just build a box that matches the internal volume of the Adire designs.

I don't need to go with a second sub, this one puts out more then enough for my room. My current sonosub hits below 17Hz and I'd like to keep that or go a bit lower if possible.

I do have more then 1' to work with, maybe 16" but I'm not 100% sure until I take some measurements.

So, can someone help this math **** out and figure out how may cubic feet are in a 24" x 36" cylinder

tryrrthg

Originally posted by Ron-P
I don't need to go with a second sub, this one puts out more then enough for my room. My current sonosub hits below 17Hz and I'd like to keep that or go a bit lower if possible.

I do have more then 1' to work with, maybe 16" but I'm not 100% sure until I take some measurements.

So, can someone help this math **** out and figure out how may cubic feet are in a 24" x 36" cylinder

Well take a look at the Adire designs. They'll give you the design specs you just have to figure out a box that gets the same volume as theirs.

volume of cylinder = pie * radious^2 * height.

so yours is 9.42 sq feet. or 266.88 liters.

Here is a handy conversion tool (it's in the middle of the page)

Ron-P

Thanks tryrrthg.

Using the calculator, I can build a box that is 4' long, 2' deep and 1.2' tall which comes out to 9.6 cf which is real close to my current sonosub at 9.42 cf. I can up fire mount the sub and port the sids of the box with my current port kit and nothing should change as far as base quality.

To get the ESB allignment I'd have to go quite bigger in terms of box size which might be difficult.

tryrrthg

Originally posted by Ron-P
Thanks tryrrthg.

Using the calculator, I can build a box that is 4' long, 2' deep and 1.2' tall which comes out to 9.6 cf which is real close to my current sonosub at 9.42 cf. I can up fire mount the sub and port the sids of the box with my current port kit and nothing should change as far as base quality.

To get the ESB allignment I'd have to go quite bigger in terms of box size which might be difficult.

sounds good, just make sure those measurments get you an INTERNAL volume of what you need. Also, don't forget to factor in some bracing, as it will take up internal volume. you'll definitely want bracing for a box with panels that big. I would just make some braces that have a giant circle cut out of the middle, that way it's easy to keep track of the internal volume they take up.

Another thing to consider is the driver position. I don't know that I'd have it firing up if the cabinet is only going to be a little over 1 foot tall. The back wave inside the enclosure could cause problems. I don't know all the specifics behind this but I've read a few people post about it at the HTF DIY section. So you might want to consider mounting the driver on the side and the mount the ports on the opposite side, basically just like your sonosub is now.

Ron-P

A valid concern. I can add a few more inches to the height and shorten the width of the box if needed and do as you suggest. I figure I'll include 2 internal braces.

gatemplin

Another thing to consider is the driver position. I don't know that I'd have it firing up if the cabinet is only going to be a little over 1 foot tall. The back wave inside the enclosure could cause problems. I don't know all the specifics behind this but I've read a few people post about it at the HTF DIY section.

I believe the theory is that the back wave reflects off the rear of the enclosure and hits the diaphragm causing coloration. I think you can lessen the affects by lining the back with lots of polyfil.

Ron-P

After doing some more research I've decided to go with a wall mount IB design. I'll build a wall mount box to mount the Tempest to and use the existing hole (where the A/C unit is now) for the back of the Tempest to exit.

If it works well I'll order up a second Tempest and run two, that should work and I'll not have to worry about a huge sub-box in the room .

gatemplin

That sounds like a good plan Ron. I think you will need a second Tempest for that room. ThomasW or Pete Mazz at HTT can help you design it.

Ron-P

Just a few hours ago I jumped into an existing thread over there with someone who did some testing with a single Tempest IB and was pleased with the results.

I'm sure 2 would be a perfect set-up for my room but I want to try one before dropping the coin for a second.

gatemplin

I hear ya. You might as well give one a try and it is easy to add a second (or fourth like Mike Knapp) later.:D

tryrrthg

Excellent choice Ron! I wish I could give IB a try, but it's not going to happen in my house.

Didn't you consider an IB once before and decide against it? What changed your mind?

Ron-P

You are correct tryrrthg, I did, but at that time I did not have a big problem with the placement of the sonotube so it wasn't a big issue, it was going to be more of a fun to try project. Now that I want rid of the sonotube I have more motivation to go IB. Also, I am very pleased with my sonotube and so I had the mindset of why mess with a good thing so that dissuaded me from going IB as well.

Base can be such a pain in the arse. Building boxes take time and the sound may not be pleaseing. At least going IB will be a quick and simple build/install. Hopefully in the next couple of weeks I can test out the one I have and see how it sounds. If at least as good as my sonotube I'll order up a second Tempest and do a permanent install.

Ron-P

Some concerns I do have with this IB config is how much sound will fill the garage and translate into the house. Now, with the sonotube almost nothing can be heard or felt in the house unless are very high levels. Also, have the Tempests less then 24" away from the garage door, how much will the garage door rattle?

It's always something.

For now though, I've got several weeks of getting the screen wall up and done so that will allow me some thinking time before jumping on the IB bandwagon.

gatemplin

If you want to know how much noise a two Tempest IB will make in the house and if it will shake the garage door, move the sonosub into the garage, shut the theater door and fire it up. That will displace about as much air as two IB Tempests and should give you a pretty good idea.

Ron-P

A good idea, several others have suggested the same and it will be done. This will be the biggest factor on if I go IB or a new box.

I really want a duel Tempest IB but don't want to upset neighbors or anyone inside the house.

Once I get my screen wall project complete I'll turn my focus to the new sub design. Due to the screen wall project the rig is in shambles until it gets completed so I can't test the sonosub outside for a few weeks.

goingganzo

i think you will get the same sound level on both sides of the wall. and you should not rattle the gurage door at all. just to let you know i am upgradeing stryke force to dual 18

Ron-P

I just finished framing up the screen wall last night. Tonight I'll get it painted and my screen mounted. Hopefully I'll get the sound system up and running by the weekend so I can stick the sonosub in the garage and give it a test.

There have been several suggestions to building the IB and a couple of them will work.

It's to the point now where it's all going to hinge on how that sonosub sounds in the garage. A good test disk will be Master and Commander.

Dr. Spec

Ron, do you still have the IB transition box plans I sent you last year?

IB is the WTG. If the sound is too large in the garage, just frame up a big enclosure outside of the Driftwood for the IB sub.

Check the Cult IB website, but the volume needs to be like 4 (minimum) to 10 (optimum) times Vas in order for the woof to truly operate in free air.

An external subwoofer enclosure won't be that big, even with dual Tempests.

gatemplin

Hey Doc, nice to see you around here again. Ron is also getting help with this from ThomasW who is the cult leader.

Ron-P

Hey Doc,

Yes, I do have them. Right now I just want to get the theater back together and running then I'll have much more time to spend with the sub situation.

Dr. Spec

Been busy with a trip to 2005 CES and some sub reviews for Secrets.

The PSW505 is currently running in my theater as a review sub. Thought you guys might want to see what she'll do.

Regardless, I'm glad Ron is leaning toward IB. In a small theater like the Driftwood, it would be ideal. I think dual Tempest would be totally tasty, with tons of headroom and low distortion.

RuSsMaN

Ditch the Tempest.

Go IB baby. How many 15's can you fit on the rear wall, or ceiling?

Cheers,
Russ

Ron-P

I have plenty of room on the rear wall but I was told by others not to put subs near seating due to localization and blending with the mains and center.

I did try a sub once buy my couch in my old theater and it was for not. Too localized and boomy sounding.