My Tumult is up and running

Discussion in 'Home Theater Projects' started by Greg Yeatts, Jul 15, 2003.

  1. Greg Yeatts

    Greg Yeatts Second Unit

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    Wow! The Tumult can really play loud. It's clean too. I have it mounted in a 6.15 ft^3 box tuned to about 19.5 hertz. I am using a Keiga 52100, 1,000 watt plate amp from Kyle at Acoustic Visions. I only listened to a little music (Big Head Todd and the Monsters Perfect World) and a snippet of a movie (Star Wars Episode II).

    I already said it was loud, but I must tell you, everything that was not hot glued to a vertical or horizontal surface in my room was set abuzz by the monstrous output of this beast. Everything in my house loved the sound of this beast so much that it started vibrating in sympathy with the sub at higher output levels. I am really going to try to isolate some of these rattles. My wife was returning from a shopping trip and she states that the front door to the house was shaking in its frame. Any suggestions?

    Also, I have not tuned the beast with my BFD (I have room modes aplenty so this test is not the final word on sound quality).

    In the near future I hope to post my models used for designing the beast, some construction pics, some finished pics and some pics of the frequency response of the finished product.

    Do any of you have any recommendations for free webhosting? I would like to establish my own website for the beast.
     
  2. Allen Ross

    Allen Ross Supporting Actor

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    i can hook you up with some free hosting i have about 50MB on my UNI account not being used, if yo can write the HTML i can just plop it up there,


    Other then that I would stay away from Tri Pod and a few others cause the don't alow hot linking which sucks for forum posting
     
  3. Greg Yeatts

    Greg Yeatts Second Unit

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    Allan

    Thanks for the offer. I may take you up on that.

    Jack

    I can''t begin to tell you how big a problem that the sympathetic rattles are. The sub is over in the corner, cleanly shaking away. Meanwhile, a/c ducting, windows, doors and every knick knack we have on any shelf in the house is making noise. It will take a while to get my room quieted down.

    I can say that the opening five minutes of Star Wars Episode II was played and the sub itself hung right in there. My old sub eventually tore its spider trying to keep up (this is my fault actaully).
     
  4. Allen Ross

    Allen Ross Supporting Actor

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    wow get some pics of the torn spider
     
  5. Allen Ross

    Allen Ross Supporting Actor

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    minor details [​IMG]
     
  6. Kyle Richardson

    Kyle Richardson Screenwriter

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    Greg, I'm sorry but the only solution is to isolate the room in 3' of cement. Sorry I forgot to tell you sooner [​IMG]
     
  7. Greg Yeatts

    Greg Yeatts Second Unit

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    Kyle

    That is probably mostly true. I am not sure I will ever be able to isolate the a/c ducting rattle as it is in a wall.


    BTW, so far I am very impressed with the Keiga 52100. I have the output on my HT receiver set on -4 and the gain on the amp is 1/4 of the way up and the Tumult will play Star Wars Episode II at reference levels. I guess the room gain worked with the Tumult a little better than I had previously thought.

    One question. When you use the Dolby/AC3 input on the amp, is the internal crossover bypassed? With the crossover on my receiver, I don't need the crossover on the amp.
     
  8. Kyle Richardson

    Kyle Richardson Screenwriter

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    The Keiga crossover cannot be defeated so just turn it all the way up as to avoid it interfering with the receiver's crossover.
     
  9. Greg Yeatts

    Greg Yeatts Second Unit

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    OK... The Tumult has been up and running for a while. I have it mostly equalized for room modes. I have one troublesome mode at 45 hertz that has proven hard to deal with. It is a 12 bump. If I put in 12 bd of cut at the offending frequencies, I only get 6db attenuation of the hump. When I cut enough to completely eliminate the hump the 45 hertz region (and only that region) seems lifeless.

    Anyway, the output of the Tumult is incredible. The only way I can describe its quality is squeaky clean. The sound is effortless. Even on DVDs that caused my other sub to tear its spider.
     
  10. Mark Seaton

    Mark Seaton Supporting Actor

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    Mark Seaton
    So far as the 45Hz peak, subjectively you often don't want to entirely notch it out flat. That said, try measuring with more tightly spaced tones, and narrow up the filter. One major problem is that you can often notch out too much of the adjacent band as you increase the cut. Realize that as you increase cut, you take with it a bit more bandwidth.

    Rather than cutting this peak, why not try moving the sub? I presume you have some distance in your room close to 13' or 25'? If you have a 25' long dimension, try placing the sub at the midpoint of this wall.
     
  11. Greg Yeatts

    Greg Yeatts Second Unit

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    I originally used 1/12 octave sine wave test tones. I then mapped the hump out at 1 hertz intervals. The hump starts at about 39 hertz, is centered at about 45 or 46 hertz and runs to about 53 hert. My euqalization is a mirror image of the bump. I used Gomer's BFD spreadsheet from the FRD consortium to calculate my eq.

    Unfortunately, we are talking about a 175 liter cabinet in my family room. The room has a lot of furniture. It is in the only spot big enough to house it. SAF would also be lower in other places.

    While I would like the sub to be mostly flat, it certainly sounds good as is.
     

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