Tumult in 16" cube vs. SVS 25-31 PC+ (1 Viewer)

[Randy G]

Brian,

Yes, I believe I failed my logic class in college. That would indeed imply 100db anechoic.
As for the Dan v. Danny, it has been rectified, clarified, tied and dyed.

 

[Neil Joseph]

Sorry to chime in late but how would this Tumult driver perform in a 4.0ft^3 (net) sonotube enclosure with 6" porting? I would probably use a built-in plate amp for this setup.

 

[Anthony_Gomez]

Neil..not good. If we put you at a "high" tunning of 20hz (responce still is flat), with a 6" port, you need it to be 42.5" long!

Lets say you do manage that port length:
Unless you have something like the HS500, then a plate amp will mean anywhere from 350-250watts. Lets say 350.

You will cross the 15ms mark at about 23 hz and will max out at 19 at 18hz. While this isnt too much in terms of port noise, you are hardly using the drivers excursion....only crest at about 12mm until you go below tunning.

At 20hz, you are looking at about 109db anochaic.

I'll let you decide if you think it is the way to go...but IMHO, I think it is a waste of a driver.

 

[Craig Woodhall]

am I wasting the driver in a 24" cube (double walled) 19" inside dimensions.. With 800w and 2 Stryke 18" PRs, tuned to 18hz.. I would rather not use the driver to its fullest.. It's nice to not have to cringe about bottoming the driver and still having a little headroom when its cranked to reference levels. This will just be one of my enclosures to fill out the bottom end.
Craig

 

[Brian Bunge]

Craig,

You lost me on your math. If building a 24" cube, double-walled, the inside dimensions would be 21". Not 19". So is it 21" or 19"?

In the 21" internal cube (151L) dual Stryke 18" PR's with 2500g each gives you an F3 around 18.5Hz. With 800W applied (which I believe is what a single channel of my K2 is rated @ 4ohms) you're above 110dB, anechoic, from 16Hz up. You get a max SPL around 114dB. The PR's don't exceed their Xmax until you get down to 15Hz.

With the 19" cube (112L) and the same PR mass you have an F3 around 20Hz and are above 110dB from 18Hz up.

 

[Craig Woodhall]

Brian,

the box is 24" on the outside, with 3/4" walls (22.5" inside) then inside that is another box with 3/4" walls.. So the total inside would be 19.. No?

Craig

 

[Lewis Besze]

It is,you have to take the thickness at both "ends".
I have a same cube.

 

[Craig Woodhall]

yes, it is the one from Stryke's page..

Craig

 

[Dustin B]

Um. Two layers of 3/4" mdf per wall. So you end up with walls that are 1.5" thick. So if the outside dimension is 24" then you take off 3" (two walls) you get an inside dimesion of 21".

 

[DanWiggins]

Randy,
As others have said, this is anechoic. Considering what the other subs mentioned in this thread can do at 20 Hz, the sealed Tumult with 750W of power should pull away from them all.
As far as the AV12 numbers go, take them with a grain of salt. Not because of the driver, but because of the tool. WinISD does not calculate output correctly, nor does it show excursion. WinISD Pro is much more accurate, and does show excursion.
Per LspCAD Pro (a $500 tool that's quite accurate), the AV12 box mentioned above (14" cube, I'm assuming internal dimension, and 500W) has the driver reaching full excursion at 20 Hz, and generates around 95 dB SPL output at 20 Hz.
Dropping a Tumult in the exact same box (never mind I'm not sure how to mount the driver in that small of a box), and using the same power gains you a good 1 to 1.5 dB across the board. And you can add another 6 dB by increasing the power even further to around 1600W for the Tumult (AV12 is at its excursion limits with 500W). Here's a graph of the anechoic output of the drivers, in the 14" cube:

Note that with 1600W of power at 20 Hz, you are pushing the Tumult to its excursion limits in the sealed box; of course, you are also at ~102 dB SPL, anechoic. Or about what you'd get from a pair of HGS-15s ($5000 worth of subwoofers). I think it would give just about any subwoofer on the market a serious run for its money, if not a sound thrashing. And this is in a 14" cube (probably a 16" external cube, assuming 1" thick walls). Hmmm... Tumult, Rava sized box, A1500 plate amp, I think I might have a new idea for what I'll run at home...
Dan Wiggins
Adire Audio

 

[Randy G]

Dan,

Thanks for the info.
Unfortunately, the 14 and 16" cubes are Exterior dimensions. It seems pretty darned tough to squeeze in a Tumult into that size. As for me, I'd be looking at the 14" cube as a competitor to the HGS-12. My bro has the space for a bit larger sub and is considering the 25-31 PC+. From a price point of $775, it seems pretty hard to beat the SVS. As for the Velo, I can get it at cost, but am open to ideas at the under $1000 price point....but in the same size as the Velo. Brian has some ideas about the AV12, so we'll see.

 

[Lewis Besze]

Um. Two layers of 3/4" mdf per wall. So you end up with walls that are 1.5" thick. So if the outside dimension is 24" then you take off 3" (two walls) you get an inside dimesion of 21".

OOps!
You're absolutely right!
I should lay off the crack in the mornings!

 

[Craig Woodhall]

Sorry guys, too much MDF dust and glue you're right.. 21" inside dimensions..

Craig

 

[Randy G]

Lewis,

a) I'm sure your wife will be relieved.

b) Just pull your pants higher so as not to expose it.

Choose one of the above. :^)

 

[MikeAcc]

Dan,

or anyone else, can you give me a good size sealed box for a single Tumult??

I have the Win Isd, it is showing me a 1.9cuft box, that does not seem right to me.

Size of box does not matter to me. Not sure what amp I will use yet, but I plan on 1000 minimum, possibly one of the Stryke amps john is asking for input on.

I would prefer a box towards SQ first.

TIA