Tempest-X 15" on order!

**pappaj** · **11-10-07, 01:08 PM**

I just put my order in for the Tempest-X it should be her soon

. Anyone have any suggestions for sonosub design using tempest. I have a piece of sonotube 5'4" long 24" dia. I am hoping someone here is using this setup for this sub with good results. I would like to go big as possible and tuned as low (within reason) as possible. The gross volume of the tube now is 475L so I have that much to work with, I'm sure this is to big.

**Geoff St. Germain** · **11-10-07, 01:22 PM**

There's probably not many, if any, using that sub in that setup yet since the driver is so new. That's not to say anything about it's performance in such an enclosure. I haven't done any modeling with this driver yet, so perhaps someone who has will be along to give their input.

**warnerwh** · **11-10-07, 03:52 PM**

Ask Kevin who you had to order it from. He'll be happy to model it for you I think.

I'm looking forward to your build and review thread. Get ready.

**Mike P.** · **11-10-07, 07:58 PM**

Your build is the first I aware of with the Tempest-X. I'm looking foward to it!

**brent_s** · **11-10-07, 08:06 PM**

When I was peeking at diycable the other day, Kevin had posted application white papers for both Shiva-X and Tempest-X. I would imagine those would be a good place to start working up a design. You can download WinISD Pro or Unibox and play around with Kevin's alignments to see what altering enclosure size, tuning frequency, diameter and/or number of ports, input power, etc. do to the overal performance of the design.

-Brent

**WillyD** · **11-10-07, 10:47 PM**

**pappaj** · **11-11-07, 06:36 AM**

Thanks Willy,
You really think I need an 8" port, It really doesn't make a difference to me. Those graphs look good to me

. I would like to complete the build before the sub arrives. The only thing I will have to buy is port material. I have lots of 1.25" mdf. See I told the wife if will come in handy someday. I will probably start building on monday.
If I don't get too carried away I will take some pics.

**WillyD** · **11-11-07, 07:43 AM**

Well no, you don't need an 8" port, but since you can easily fit one in to your design you should go for it. With high excursion 15s, 6" ports are somewhat of a limitation down low. With your relatively large enclosure volume, you can tune to 15Hz with an 8" port and still be OK as far as the 1st port resonance is concerned. You'd never have to worry about port compression, turbulence, or noise with the 8".

**pappaj** · **11-11-07, 08:55 AM**

That sounds good maybe I'll grab an 8" tube today.

**buggers** · **11-13-07, 09:59 AM**

The only problem may be the length of the port is pretty long and it can pick up resonances inside the tube. I have used as well as many others a 6 inch port at about 27.5 - 32 inches and it works great with no chuffing.

**zjason** · **11-15-07, 02:52 PM**

I love the original Tempests - I have 2 myself (see attached for some motivation).

215 Litre adire alignment (~7.5 cubic feet)
2 x 3" flared vents at 12" each
4 x 3/4 MDF disks inside (2 top, 2 bottom)
Veneered plywood on outer
Behringer EP2500, 1 channel per sub

I look forward to your build!

**WillyD** · **11-15-07, 02:55 PM**

Quote:

buggers wrote:

The only problem may be the length of the port is pretty long and it can pick up resonances inside the tube. I have used as well as many others a 6 inch port at about 27.5 - 32 inches and it works great with no chuffing.

The length I suggested is within the acceptable limits. And sure many folks have used 6" ports with 15 drivers and had no issues, including myself. That doesn't mean the OP should settle for 6" when 8" is doable.

**Kevin Haskins** · **11-15-07, 03:08 PM**

Yes... on a driver with this much output the port becomes the limiting factor down low. An 8" port is not overkill. You may get into port resonance issues with really long lengths. If you go with the 340L design and a 32" long 8" port you should have a killer sub. Flare both ends as it really does make a difference.

**pappaj** · **11-15-07, 09:52 PM**

Well Kevin,
It's nice to see you here at the shack. I'm sure your knowledge will be appreciated. I've heard some talk that some people have been trying to lure you in to the shack, I see there plans have came through.

**pappaj** · **11-15-07, 10:10 PM**

I have the top and bottom plates completed. Tomorrow I am going to put the foam inside the tube and fasten the port to the top plate. I also have to make spacers and the floor plate. I also bought some stretchy fabric to make the sock, as soon as I find someone that can sew it for me. It's coming along nicely. I should be finished the build by the time the sub is here. I can't wait.

**SteveCallas** · **11-18-07, 02:06 AM**

Wow, this driver loves volume and maintains a well damped low end, it is absolutely perfect for SLLT use. Check out 4 of these in 4000 liters with two 12" diameter ports that are 26" long - looks great and truly makes me wonder why anyone would go IB if they had the choice.

As for a single driver LLT solution, I'd personally go a bit larger than Willy is suggesting - no lower than 500 liters for a 15hz or lower tune with this driver. If you are willing to go that large though, you may as well leapfrog this driver and get an 18" solution.

But if anyone was on the fence for a SLLT, this driver looks like instant success.

**WillyD** · **11-18-07, 01:23 PM**

Quote:

Wow, this driver loves volume and maintains a well damped low end, it is absolutely perfect for SLLT use. Check out 4 of these in 4000 liters with two 12" diameter ports that are 26" long - looks great and truly makes me wonder why anyone would go IB if they had the choice.

You're a little late there pal. I suggested the same exact thing about the drivers that these were spun off of, but you shot the idea down saying that "4000 liters is just too big for four 15inch drivers!" and some other non-sense like that. But I guess if it comes from you its ok.

Quote:

As for a single driver LLT solution, I'd personally go a bit larger than Willy is suggesting - no lower than 500 liters for a 15hz or lower tune with this driver. If you are willing to go that large though, you may as well leapfrog this driver and get an 18" solution.

Did you miss the part where he already has a 5ft 4in long 24" diameter piece of sonotube? What else was I supposed to suggest? Surely you wouldn't have him go buy another piece of sonotube...

**SteveCallas** · **11-18-07, 02:09 PM**

Down sparky, down.

When did we discuss this driver in SLLT use before?

**WillyD** · **11-18-07, 03:20 PM**

A few months ago we discussed its predecessor in SLLT. Besides the fact that you didn't like it because it was from a small "defective" production run, you suggested it was ridiculous to use just four 15" drivers in such a large enclosure. We went through this in PMs.

And don't call me sparky. I just call it out when you blatantly shoot down someone else's suggestion but then bring it up again months later like its such a great idea.

And I think the 415l net @ 15Hz is still provides for a great FR. You tend to suggest FRs that aren't quite so damped, and I dunno why.

**SteveCallas** · **11-18-07, 06:56 PM**

Are you talking about the small run of drivers that were a mistake and would never be made available again? These drivers are different if I'm not mistaken. I find it strange that I would say something about size being too big if it were for SLLT use, as size doesn't matter at all in a SLLT. Stand alone enclosure use, then yeah, these 15" drivers aren't worth the real estate when an 18" would work better, unless these are really cheap.

**Kevin Haskins** · **11-18-07, 08:37 PM**

The only difference between these drivers and the XJ is the Cms (of course the parameters dependent upon the Cms changed with it). The XJ's where much stiffer and ended up being great for IB or dipoles but didn't hit our target parameters, which was a replacement for the old Shiva & Tempest with a better motor.

There is something to be said for using an 18" if you want a large enclosure. You typically get an Sd around 1080 cm^2 compared to about 790 cm^2 of a high stroke 15". Most 18"s that have this much stroke though get pretty expensive so you have to make the choice on a driver - driver comparison. Rather than starting with a driver size in mind I'd start with a budget, size & performance goal and try to figure out the best solution based upon that goal.

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