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Discussion Starter · #1 ·
I have about 2 months now before I can build but I want to get everything nailed down in the design before making a single cut. I was looking at the Shiva but now thinking Tempest. This will be a sonotube design with a 16" tube.

Total Height is 58"
Distance between sub and base is 3½"
Distance between port and top is 3½"
Volume is 5.17781²
Port lenght end to end is 31"
Port length that is straigh is 27 7/16"
Distance from driver to port flare is 9¼"
Distance from driver to straight port is 12¼"

For a few questions.
1. How do you calculate port length? Do you take in account of the flare or just what you need straight?
2. How far should the port be away from the driver? And is it ok for it to be point straight at the sub?
3. Does the Application guide take in account driver displacement? My model is 5.17781 but the driver takes up part of that space.

TIA. I will do a full build log after the holidays.

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You can't DO things like that! :unbelievable: I feel like a fool with all my scratch paper with scribbled drawings and such.:nono:

To answer your questions:
The sonosub.exe program gives you total length, including flare thicknesses if you select the option for one or both, if I remember correctly.

It is standard design to have the port staring the driver in the face, just not too close. Again, the sonosub program will give you a warning in red, along with the distance between them.

There should be a place to enter driver displacement in the program as well, under driver parameters to account for the displacement (it's not much volume, .1-.2ft^3)

The only thing I see that concerns me relates to how the legs are attached (which I really like), if you have screws on the internal edge of the tube holding the legs, then the endcaps won't be able to slide into the tube's end? No? The tube is cardboard, so a recessed or regular screw may pull through, so perhaps you're planning to install the legs after the endcaps are installed, so you have the endcaps inside for the threads to bind to?

For my benefit, please scan and upload a scribble-note next time in lieu of this awesome drawing:D
 

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Discussion Starter · #3 · (Edited)
Glen, Thanks for the compliments. I use to be a paper and pencil guy. Then on one deployment I learned Google Sketchup and it has been down hill from there. I must have searched for the sonosub.exe a hundred times and it finally came up today. I was close, infact really close to all the measurements. I have to adjust the flare on the ports a little but the rest is almost spot on. I think it might even have to do with the way things are rounded up and down.

The plan so far is to build the tube with each end installed. I want to then veneer the sides covering over the plugs. Then veneer the top and bottom. After that I will drill, countersink and screw & glue the legs on. Probably will have to make a jig or 2 to line everything up true.

I could also put a step into each leg it just means a little more work.

Edit: I also added the Tempest to the 3d warehouse if anyone is interested. All the measurements are taken from the manual and based off pictures. Use at your own risk!! http://sketchup.google.com/3dwarehouse/details?mid=4c68944b2b8105d11a2f7b80918eee9d

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It looks awesome...... great work.

If you have the flexibility, you may want to go slightly larger for the enclosure volume. It is easy to pick up space with the large Sonotube, much easier than with a box. I like about 7 cubic feet (200L) with a single flared 6" port tuning the enclosure to 20Hz (22" long port). Larger enclosure volume translates to a shorter port and a single 6" flared port is big enough that you will never get chuffing. Keeping the port short, keeps the first resonance well up out of the bandwidth of the subwoofer.

None of the simulations account for the port volume, driver volume or amplifier volume so you have to subtract them all from the total. Since it is Sonotube, I assume you will be using an external amp. The Dayton Rack-mount 1000W subwoofer amp is a good turn-key solution because it has the 18Hz subsonic filter already in place. They are $400 shipped so more expensive than the 500W but it rack mounts and gives you a little more power.

Simulation of the above...



Kevin Haskins
Exodus Audio
 

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Discussion Starter · #5 ·
Kevin,

I was wondering what you would recommend if your amp doesnt have a Subsonic Filter. I have a opportunity to purchase a Behringer EP2500 for less than most plate amps. I have been looking for what I need but have found that I might be over my head. I can find EQ's that have Subsonic filter to 25Hz but not 18Hz. Not to mention most of them would be more expensive then the amp and sub put together.

I received my Tempest last Thursday and was finally able to open the box Sunday. All I can say is that Subs have come a long way since high school. I use to have 4 15"s in the back of a Ford Festiva and I bet all 4 of them weight as much as 1 Tempest I cannot wait to get this sub built. I am waiting for the veener and sonotube to arrive. I guess 16" tube is not standard size here in Florida.
 

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Kevin,

I was wondering what you would recommend if your amp doesnt have a Subsonic Filter. I have a opportunity to purchase a Behringer EP2500 for less than most plate amps. I have been looking for what I need but have found that I might be over my head. I can find EQ's that have Subsonic filter to 25Hz but not 18Hz. Not to mention most of them would be more expensive then the amp and sub put together.

I received my Tempest last Thursday and was finally able to open the box Sunday. All I can say is that Subs have come a long way since high school. I use to have 4 15"s in the back of a Ford Festiva and I bet all 4 of them weight as much as 1 Tempest I cannot wait to get this sub built. I am waiting for the veener and sonotube to arrive. I guess 16" tube is not standard size here in Florida.
If you are on a budget, the plate amps (or rack-mount 1000W unit) make good sense because they already have the subsonic filter that you absolutely need. They also don't have fan noise, so you don't have to either modify the EP-2500 or remote mount it.

There really are two choices, either the SMS-1 which does room measurement & EQ along with a software adjustable subsonic filter, or one of the boxes that have a simple analog filter. If it were me, I'd get the SMS-1. Save your pennies, mow the neighbors lawn, shovel snow, do whatever needed to find the money for room measurements and EQ. It can make a profound difference in the final results.

Kevin Haskins
Exodus Audio
 

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If you are on a budget, the plate amps (or rack-mount 1000W unit) make good sense because they already have the subsonic filter that you absolutely need. They also don't have fan noise, so you don't have to either modify the EP-2500 or remote mount it.

There really are two choices, either the SMS-1 which does room measurement & EQ along with a software adjustable subsonic filter, or one of the boxes that have a simple analog filter. If it were me, I'd get the SMS-1. Save your pennies, mow the neighbors lawn, shovel snow, do whatever needed to find the money for room measurements and EQ. It can make a profound difference in the final results.

Kevin Haskins
Exodus Audio
Kevin, are you kind of forgetting your own SC-1250 amp? It wouldn't give him measurement capability, but the testing in the amp thread at AVS suggests it has a highpass in the 15-18Hz region when configured in the generic subwoofer mode. Use REW for the room measurements and one of the $100ish Behringer to do the EQ, if needed. If he's equipped with Audyssey, it's been good enough for some of us without the need for additional EQ.

-Brent
 

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Kevin, are you kind of forgetting your own SC-1250 amp? It wouldn't give him measurement capability, but the testing in the amp thread at AVS suggests it has a highpass in the 15-18Hz region when configured in the generic subwoofer mode. Use REW for the room measurements and one of the $100ish Behringer to do the EQ, if needed. If he's equipped with Audyssey, it's been good enough for some of us without the need for additional EQ.

-Brent
It would work.... I only have one. After it is gone, I won't carry any more. The only way they sell is if I sell them at a loss so that isn't a great long-term business concept.

Kevin Haskins
Exodus Audio
 

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It would work.... I only have one. After it is gone, I won't carry any more. The only way they sell is if I sell them at a loss so that isn't a great long-term business concept.

Kevin Haskins
Exodus Audio
But, I thought selling widgets for less than cost was how the new internet economy was supposed to work. Right up there with "the more you spend, the more you save". :scratch:

Seriously, sorry to hear that "sale" price is unsustainable. If/when I decide to build a sub needing power in the 1Kw range, the SC-1250 from you was on my short list.

-Brent
 

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But, I thought selling widgets for less than cost was how the new internet economy was supposed to work. Right up there with "the more you spend, the more you save". :scratch:

Seriously, sorry to hear that "sale" price is unsustainable. If/when I decide to build a sub needing power in the 1Kw range, the SC-1250 from you was on my short list.

-Brent
Yea... some of the things people believe about economic realities is hard to fathom. It at least explains our current economic situation.

Kevin Haskins
Exodus Audio
 

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Discussion Starter · #12 ·
Modeled after the X2. I have to say pretty close. I havent broken out a micrometer or veneer caliper. That is why it is a use at your own risk:bigsmile:
 
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