Who has actually built Dan Wiggin's 175L Vented Tempest design?

Discussion in 'Home Theater Projects' started by Sven_DP, Apr 29, 2003.

  1. Sven_DP

    Sven_DP Agent

    Joined:
    May 21, 2002
    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    Some time ago I found what could be called a 'non-official' 3rd Tempest alignment on this forum, vented and at 175L. I have been putting the figures into several programs, but I don't seem to be able to duplicate his results.

    - 175L net
    - Fb = 17,5 Hz
    - 10,2 cm port dia(4")
    - 43,2 cm port length
    - 150W - parallel connected
    - Stuff 100% (20gr. / liter)
    - F3 = 22 Hz anechoic

    Depending on fill (Qa) and leaking (Ql) I'm getting an F3 between 24,8 and 30 Hz, so not even close to 22Hz.

    After heaving read Tom Noussaine's article on stuffing I was under the impression that 100% stuffing should be avoided because it makes things worse. So why 100%?

    Going up to Fb = 19 gives me an F3 = 23,13 Hz which was the design I mentioned at the beginning of my thread about Sealed/Vented Tempest enclosures. Still I would like to be able to simulate Dan's design as close as possible.

    Has anyone calculated, simulated, built or heard this 175L design yet?

    Btw. Replacing the Tempest by a Shiva lowers Fb and F3 easily to 17-18Hz. Would this be better for my 70/30 music/movie usage, just giving up a little SPL?

    I already asked this question in another thread but on this particular question I didn't get any hands-on experience...

    Thanks for all reactions and remarks.
     
  2. Kyle Richardson

    Kyle Richardson Screenwriter

    Joined:
    Jan 1, 1998
    Messages:
    1,073
    Likes Received:
    0
    Trophy Points:
    0
    I helped build a local customers pair of 175L ported Tempests. I cant remember the exact details such as box tuning or their in room F3 but they were stuffed with approximately 5lbs of poly each and they sounded awesome.

    These were in addition to his pair of ~110L double shiva subs matched to some electrostats that he used for music. Yes, that is 4 shivas and 2 Tempests in the same room! He would use the Tempests for HT and the Shivas for music and the room sounded awesome! He had the Tempests corner loaded and the Shiva subs right next to the mains.

    So basically what I'm saying is that you dont have to match a "pre-set" alignment. Just simulate it on the computer and then if it looks good build it!
     
  3. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,766
    Likes Received:
    489
    Trophy Points:
    9,110
    My Sunosub III is close to that alignment, except, I tuned it much lower (with stuffing, the Fb was around 13Hz) with a 22" long 4" wide flared port, and it was stuffed with 4.5 pounds of polyfill. Look for it in my DIY Project link below.
     
  4. Sven_DP

    Sven_DP Agent

    Joined:
    May 21, 2002
    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    Kyle, Patrick, thanks. I also think that I will simulate on PC and just build it. Problem is that I can't simulate Dan's design.

    Furthermore, the more I read about stuffing and leaking, the more I'm getting doubts. I've been playing around with the settings in unibox (light stuffing, walls covered, heavy stuffing) and with he percentages in LspCAD, but it's giving me strange results. Unibox gives me the lowest Fb and F3 values with no stuffing at all. I thought it was all about increasing the volume or at least pretending to do so... So what's best?

    Also, I wonder how one can influence the Ql values by deliberately changing the 'air leakage' of the sub.

    Kyle, do you suggest that the Shiva is more suitable for music than the Tempest? I can get a much flatter response curve with a Shiva at the expense of a little bit SPL and taking into account a much steeper curve below the Fb tuning point.

    Thank you all. Sven
     
  5. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,766
    Likes Received:
    489
    Trophy Points:
    9,110
    You can simulate all day long, but much is theoretical, and the room/placement of the sub will have just as much impact on its performance as the gnashing of teeth on simulating the effects of leakage/stuffing that most of the little bitty details offset themselves in the end.

    You've got a good blueprint for a sub. Just build it!
     
  6. Kyle Richardson

    Kyle Richardson Screenwriter

    Joined:
    Jan 1, 1998
    Messages:
    1,073
    Likes Received:
    0
    Trophy Points:
    0
    Shiva's arent necessarily better for music but he wanted a sealed design and also wanted effortless high SPL impact. Since we were using multiple drivers we went with the 12's and since they don't require as much enclosure space as the 15's.

    Like Patrick says, you get your basic idea from the simulation then you NEED to build.
     
  7. Sven_DP

    Sven_DP Agent

    Joined:
    May 21, 2002
    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    Need...to build...sub...anytime now...just need some holidays...[​IMG]
     
  8. Justin Ward

    Justin Ward Supporting Actor

    Joined:
    Jun 6, 2002
    Messages:
    673
    Likes Received:
    0
    Trophy Points:
    0
    The F3 doesn't equal tuning. A sub tuned to say 25hz can still output lower than that right? Albeit with considerable excursion.
     
  9. Frank Carter

    Frank Carter Screenwriter

    Joined:
    Mar 12, 2002
    Messages:
    1,187
    Likes Received:
    0
    Trophy Points:
    0
    The F3 is just where the system is down 3dB from the level at 100Hz. In a bandpass system, it's where the system is down 3dB from the middle of the pass band. It does not have to equal the tuning frequency.
     
  10. Sven_DP

    Sven_DP Agent

    Joined:
    May 21, 2002
    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    No, F3 shouldn't be equal to Fb. I wonder if it's even possible to have a tuning point which is already 3dB down.

    My problem with this design is that I'm not able to simulate it, not with LspCAD, not with WinISD, not with Unibox and not with the Ported.xls file. So I wonder if this particular design is even feasable or if I'm making a mistake somewhere...

    I have a 200L gross sonotube available, but now I'm just thinking of making a 130L net vented Shiva design and a 50L sealed one later on with the rest of the tube. Oh, maybe you're all right and on the first holiday I should start building. [​IMG]
     
  11. Frank Mowry

    Frank Mowry Stunt Coordinator

    Joined:
    Mar 25, 2003
    Messages:
    57
    Likes Received:
    0
    Trophy Points:
    0
    I'm ready to mount the Shiva in my newly finished 120L sonotube after work today. Should have listening impressions by the weekend. Full length flared 4 inch port from PE and the 250 plate amp.

    Frank
     
  12. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    We've built a couple of the 175L, 17.5Hz tuned subs. They're awesome. We had a customer that sent back his SVS 20-39CS and Samson amp because he kept bottoming the sub at reference levels. He's had no problems with this sub to date.

    IIRC, this is the same alignment that Hank built as well.
     
  13. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0
    I built it and it is not unofficial. Dan Wiggins suggested it in a post here - I tried to find it among the hundreds, but it goes back way over a year. It sounds great - never fails to drop jaws. I don't have measurement software, so I can't post a graph. I know one or two other posters built it and Brian Bunge built it. Don't agonize over it, just build it and enjoy.[​IMG]
     
  14. Brian Bunge

    Brian Bunge Producer

    Joined:
    Sep 11, 2000
    Messages:
    3,716
    Likes Received:
    0
    Trophy Points:
    0
    Hank,

    Just look up![​IMG]
     
  15. Tom-K

    Tom-K Stunt Coordinator

    Joined:
    Nov 29, 2000
    Messages:
    119
    Likes Received:
    0
    Trophy Points:
    0
    I am in the process of helping out a friend build his sub for his media room. He has 4 tempest drivers, and the Rhytmik amp. It will be about 70/30 HT/Music. We are building the subs into his front projection stage. I have the ability to build either 4 separate sealed enclosures with about 9 cubic feet per, or I can do one big sealed enclosure housing all 4 drivers, or I was also thinking about this ported design, which would you guys recommend using 4 drivers and the amp mentioned. Appreciate your input.
     
  16. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0
    Brian,
    At what, another brilliant Brian post?[​IMG]
     
  17. Hank Frankenberg

    Hank Frankenberg Cinematographer

    Joined:
    Oct 13, 1998
    Messages:
    2,573
    Likes Received:
    0
    Trophy Points:
    0

    Tom: what do you mean "into" his stage? If you can take advantage of a large space, I'd look at an IB with the 4 Tempests.
     
  18. Tom-K

    Tom-K Stunt Coordinator

    Joined:
    Nov 29, 2000
    Messages:
    119
    Likes Received:
    0
    Trophy Points:
    0
    Hank,

    The stage is actually going to be the box. It is roughly 12 ft wide, 2 ft tall & deep. For IB I think you need like 4 times the VAS. I don't think I have enough space, if I recall the VAS for the Tempest is around 11. That would mean I would need like 176 cubic feet for all four. That being said, what choice would you choose out of the 3 mentioned above.
     
  19. CarlDais

    CarlDais Stunt Coordinator

    Joined:
    Sep 24, 2000
    Messages:
    56
    Likes Received:
    0
    Trophy Points:
    0
    Sven

    I wasn't impressed with a 50L shiva. A 75L shiva
    either sealed or vented & tuned to 22Hz is a good
    choice. A 185L vented shiva, tuned to 17Hz.
    It is a good performer. 175 L sealed Tempest does
    reassonable for Music & HT. You might also consider
    a 115L isobaric Tempest. I've done this in an 18"
    sonosub. It is a Dan Wiggins desgin he came up with
    for John Morris (merc) to match (easily) the capabilities of a SVS ULTRA. It raises the cost but Isobaric Shivas or tempests will get you great performance in smaller tubes either vented or sealed. Another experienced builder did a isobaric Rava clone. Basically 65l sealed with two shivas.
    he was quite pleased & he is picky about sound.
    The beauty of a Vented Sonosub is that you can vary the tuning so much easier than a box. It makes for a very good test muule. The costs and time to build are minimal. YOu'll be amazed at how tuning form 18 hz up to 24 Hz can dramitically change the character of the sub's sound.
    And internal volume can be tweaked by adding solid items to take up space.
     
  20. Sven_DP

    Sven_DP Agent

    Joined:
    May 21, 2002
    Messages:
    39
    Likes Received:
    0
    Trophy Points:
    0
    @Carl :

    115L Isobaric Sonosub matching an SVS Ultra? Hmm, my wife will definitely like this. Today, she asked me if I was really planning to put this 200L cylinder in 'her' living room...
    I really didn't look into isobaric until now, just because I thought it wasn't possible in a sonotube. Could you please tell me how you did construct this in a sonotube? Can I find Dan's design somewhere?

    Furthermore you say 175L Tempest does 'reasonable' for music and HT. May I understand from this that you think there are better choices?

    @Frank Mowry :

    I'm not curious, but did you manage to mount the Shiva? Did it survive? [​IMG]

    Thanks. Sven
     

Share This Page