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Tumult in 16" cube vs. SVS 25-31 PC+

Discussion in 'Archived Threads 2001-2004' started by Randy G, Nov 8, 2002.

  1. Randy G

    Randy G Second Unit

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    Hi Gang,

    I was just kind of wondering which would have better performance...the new Tumult in a 16" sealed cube with some kind of LT circuit perhaps and the 750 watt plate amp or the new SVS 25-31 PC+(500 watt BASH). Any ideas for this newbie?

    Randy

    ps-Hi Bri.
     
  2. You will get more output with the SVS. A 16" cube is really small. I would use atleast 1.5" thick walls. Then take away 4L for driver displacement and you are at 32L. Then use heavy stuffing.

    With 1600watts applied, you are only looking at hitting around 22mm. Lets assume that the driver is ideal and does not suffer from thermal compression, then you are "only" looking at about 105db at 20hz anochaic (Unibox modeling). Room gain and corner loading will significanly bring that up.

    Just going up to a 17.5" cube brings it up to 46L You now are at about 27mm at 20hz with 107db.

    BUT you are looking at a 750watt amp, so subtract 3db from all of my figures.

    IMO, with a 750watt amp in 16" cube and a tumult, go with the SVS
     
  3. Brian Bunge

    Brian Bunge Producer

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    Hi Ran! Yeah, with only 750W the SVS will have the clear advantage. But put some serious power behind it and I'd rather have the Tumult.

    I wish I really had the room for the large cube with the 18" PR's!
     
  4. Randy G

    Randy G Second Unit

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    Yeah, and *I* wish I had the room for the SVS. My brother has the space, so he's quite fortunate. For me, the puny HGS-12 will have to suffice...14" cube is MY limit. Thanks for the info Anthony and Brian.

    Randy
     
  5. Brian Bunge

    Brian Bunge Producer

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    Randy,

    You physically have the room, you have just put a huge limitation on what you consider an acceptable size.
     
  6. Randy G

    Randy G Second Unit

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    Brian,

    I don't understand your comment. What do you mean by "You physically have the room...etc."???
    *MY* limitation is a 14" cube, but for my bro, he said he liked the idea of the SVS 25-31 PC+ because HE has the room. And for the price, well....I thought that perhaps your notion of the tumult in the 16" cube might be a good alternative to the SVS, but it seems the price is considerably higher.
    As you know, I'M always looking for something better than the HGS-12 in the same size cube, but it doesn't seem to exist yet.
     
  7. Craig Woodhall

    Craig Woodhall Supporting Actor

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  8. Ryan Schnacke

    Ryan Schnacke Supporting Actor

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    To me there's a good reason that this Tumult design seems too expensive. You'd pay big bucks for an extreme woofer and then starve it for power. Using Anthony's numbers you're only using about 1/3 of its potential. That's like buying 3 Tempests but only powering one of them. Bang-for-the-buck on that deal is terrible. Its like folks buying Suburbans and Expeditions and driving them around mostly empty all the time and complaining about gas mileage.

    There's a few ways to improve the situation. First, you could feed the Tumult the kilowatts it really wants. Again, using Anthony's numbers it seems reasonable to hit 110dB from a 16 inch cube with the right amp.

    Or, as Brian said, you could re-evaluate your size constraints. A bigger box would physically fit somewhere in your room.

    Or you could go with the 16 inch cube/750 watt design but use a more reasonable driver. The new Stryke AV15 seems like it'd be plenty for this. Its half the cost and 1.5dB more sensitive than the Tumult so you'd actually improve both the cost and performance - since you're power limited.
     
  9. Randy G

    Randy G Second Unit

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    Craig-

    >>24" cube really isn't all that big.
     
  10. Craig Woodhall

    Craig Woodhall Supporting Actor

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  11. Rory Buszka

    Rory Buszka Supporting Actor

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    But what is it that imposes that limit on you? Is it your bed, your dresser, or your closet? Or is it just something you consider to be aesthetically unacceptable? (I have my own opinions about people who think that a reasonable size speaker is aesthetically unacceptable.)
     
  12. Brian Bunge

    Brian Bunge Producer

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    Randy,
    All I was saying is that your size limitation was self-imposed. Unless, of course, you want to fit it in a very specific, confined space.
    And guys, yeah, Randy is a small guy![​IMG]
     
  13. Randy G

    Randy G Second Unit

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    It is to go into a living room, and yes, I find a 14" cube at the limit of my own aesthetic tolerance level. *MY* compromise was to stick the couch in the middle of the living instead of in the corner, which makes the living room appear smaller. If my living room was larger, my tolerance level would go up proportionally.[​IMG]
     
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  15. Peter_A_M

    Peter_A_M Stunt Coordinator

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    Randy said,
    As you know, I'M always looking for something better than the HGS-12 in the same size cube, but it doesn't seem to exist yet.
    I modeled a single AV12 in a sealed 14" cubic inch box and 500 watts and got got the following results at one meter:
    Max SPL ~ 111 dB
    F3 ~ 37 Hz
    F10 ~ 21 Hz
    100 dB @ 20 Hz
    Qtc = .648
    According to the information on Adire's website, this is better than the Dharman, which in turn is comparable to the HGS-15, and which in turn is better than the HGS-12.
    Are these WinISD Pro (alpha) numbers way off? If not, I don't see why you couldn't use the AV12 in a 14 cu. in. box and still be satisfied, Randy. You won't use it to its full potential, but it should perform better than the sub you have now.
    The Brahma 12 models similarly with a Qtc of .694, but I don't know how similar or dissimilar distortion levels are.
     
  16. Brian Bunge

    Brian Bunge Producer

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    Tony,
    I was speaking in general terms! Randy and I have never met personally yet, but we've been friends for around 3 years now. IIRC, he told me he's about 5'6" and about 150-160 lbs. I'm 5'9" and 200lbs. so in my mind he's a small guy! [​IMG]
    Jack,
    That's exactly what I was suggesting and what prompted Randy to start this thread. I was originally talking about the Hypex HS500 amp but wasn't thinking about the fact that it wouldn't be enough power to outgun the SVS. I was thinking more along the lines of Dan saying they had LT boards in stock and would be offering the amp, LT board, and Tumult as a package. I figured a Brahma 12" could replace the Tumult if necessary.
     
  17. DanWiggins

    DanWiggins Second Unit

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    Hi all,
    Couple of thoughts:
    1. A Tumult in a 16" cube is capable of ~100 dB SPL at 20 Hz, and still is within 60% of it's linear capability. So we're talking EXTREMELY clean output. And I think that's probably more than the PC+ could do.
    2. WinISD is NOT to be trusted - WinISD Pro is much more accurate. I would strongly suggest dropping WinISD to upgrade to WinISD Pro - even Juha and the other Linear Team guys recommend this.
    3. Note that you don't HAVE to use full excursion of a driver! Tumult with 750W in that tiny box will be pushing ~ 45mm p-p at 20 Hz. Is that the limits of the driver? No. But it's beyond the limits of any other driver out there... So you'll have more output, and it will be cleaner, than any other driver capable.
    4. Flat BL means low THD. Again, this is where only being ~3% down in BL at the ~23mm one-way excursion means extremely low THD. I'm measuring around 2% THD at this level of excursion. Other solutions/drivers will be at their 10%+ THD limit, while the Tumult solution is just loafing along.
    5. Upgradability. If you ever do want to upgrade, just add more power. Double it, and you're still within the linear limits of the driver. And pushing ~103 dB SPL at 20 Hz - ANECHOIC - in the tiny 16" cube.
    6. Fully stuffed, that 16" cube would yield a Qtc of 0.707 - fairly tight and accurate. The LT is really just for depth extension, not for Qtc augmentation. That does assist stability of the LT.
    7. The LT boards for the HS500 fit VERY nicely... Easy bolt-on, clean full solution...[​IMG]
    Dan Wiggins
    Adire Audio
     
  18. Randy G

    Randy G Second Unit

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    Thanks everybody for the suggestions.

    Dan, when you say the Tumult in a 16" cube can do 100db at 20, is that in-room or anechoic? I'll have to speak with Brian to see if it's fiscally worth doing...as opposed to the $775 25-31 PC+. Once again, it would be for my bro.

    Peter, I'll have to check the AV12 figures with Brian, but it sounds impressive. Just to let ya know, when Don Keele measured the HGS=12, he came up with the following numbers:

    anechoic-

    16hz-90 db
    20 -96
    25 -98
    30 -105
    60 -109

    in HIS room-

    16hz-99db
    20 -105
    25 -108
    30 -110
    60 -114

    Now, his room cOuLd have been the bathroom for all I know, but it's pretty impressive nonetheless for a 14" cube. Actually, I just emailed him to try to find out the room size he tested in.

    thanks everybody for the ideas,

    Randy
     
  19. Brian Bunge

    Brian Bunge Producer

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    Randy,
    If you look at Dan's #5 you'll see he mentions doubling of power gives 103dB at 20Hz, anechoic. This would imply that he was talking 100dB at 20Hz anechoic in #1.
    I haven't modeled the AV12 yet but I'll do so and email you.
    Oh, and that's Dan, not Danny! I think you're getting your companies confused! [​IMG]
     

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