Double Checking Measurements for Sonosub

Discussion in 'Archived Threads 2001-2004' started by ChristopherJ, Feb 23, 2001.

  1. ChristopherJ

    ChristopherJ Extra

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    I was wondering if some of the experienced Sonosub builders wouldn't mind double checking my calculations.
    24" Diameter Tube
    26" Internal Height
    15" Adire Audio Tempest Subwoofer
    22" long and 4" wide Precision Flared Port (from end to end)
    Samson S700 Amplifier with one voice coil to each channel running in Parallel.
    16-17 Hz tuning frequency as the goal.
    Other odds and ends info:
    3 layers of 3/4" MDF on top endcap with 2 layers internal.
    2 layers of 3/4" MDF and 1 layer of 3/4 plywood on bottom endcap.
    Tube will be lined with 1/2-1" of pollyfill around the sides (should the bottom of the top endcap be lined as well?)
    Please let me know if the numbers add up correctly!
    Chris
    P.S. I am waiting for the terminal cup as it was accidentally left out of the shipment when my Tempest was sent. I feel like a crack addict with everything but the lighter!!!!!!!!!! [​IMG]
     
  2. Patrick Sun

    Patrick Sun Moderator
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    Looks great, go for it, Christopher. Just be aware it's not totally flat to 20Hz, but it will be more than adequate. If you could find a way to go for a little larger sub, you could flatten out your frequency response a little more, but then again, I don't know what your emphasis is on: music or HT.
    ------------------
    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  3. ChristopherJ

    ChristopherJ Extra

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    I completed my sub but it is not as loud as I hoped. It sounds cleaner and the wife beleives so too. Unfortunatyly, I cannot get it to teeth ratling levels without blowing my eardrums. Any suggestions?
     
  4. Jack Gilvey

    Jack Gilvey Producer

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  5. ChristopherJ

    ChristopherJ Extra

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    That does look rather odd. What I meant was that I have to turn the systems volume so loud that the main speakers make my ears ring. Only then do I get to a subwoofer sound volume that is acceptable.
     
  6. Patrick Sun

    Patrick Sun Moderator
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    (I posted this on the other forum as well.)
    Looks like your receiver is the culprit. Is it a DPL receiver only? It doesn't output a true LFE or subwoofer signal, does it? How are you getting the signal to power the subwoofer's amp? Have you calibrated your HT system? (probably tough to do if you don't have a 5.1 receiver).
    ------------------
    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  7. Jack Gilvey

    Jack Gilvey Producer

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  8. Oliver

    Oliver Stunt Coordinator

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    Christopher:
    Can you give me the Thiele-Small Parameters of the sub,
    I would like to do my own calculation to see where something went wrong.
    Or maybe a link where I can find those.
    Thanks,
    Oliver.
     
  9. ChristopherJ

    ChristopherJ Extra

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    Jack: The amp is set at it's max and the subwoofer outpoot is at the max as well.
    Oliver: I haven't the slightest idea what the Thiele-Small Parameters of the sub are. Where/how would I get that?
    Thanks for your help!
     
  10. Jack Gilvey

    Jack Gilvey Producer

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  11. Greg Monfort

    Greg Monfort Supporting Actor

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    >What I meant was that I have to turn the systems volume so loud that the main speakers make my ears ring. Only then do I get to a subwoofer sound volume that is acceptable.
    ====
    Are you saying you can't set the mains output independently from the sub? If so, you're in trouble because the mains are supposed to be 10dB lower than the sub in playback.
    GM
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    Loud is beautiful, if it's clean
     
  12. ChristopherJ

    ChristopherJ Extra

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    Actually, I can't adjust the mains volume. I just discovered this tonight. I thought I was adjusting the level but it had absolutely no effect on the volume. I may have to borrow my dad's Denon 3300 to see if it makes a difference. Thank you for the input...any other sugestions?
     
  13. Patrick Sun

    Patrick Sun Moderator
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    Unless you are able to hook up front main speaker-level inputs through the subwoofer amp (so that it'll filter the low frequency material to the sub's amp) and back to your front speakers, I think you'll be having problems getting good bass output from the sub. This is due to your receiver not having bass management.
    But, I'm surprised that your DVD player's 5.1 output circuitry isn't doing a good job on the bass management for the DVD source material. I never did like using a "5.1-ready" receiver to get your sub working in concert with the rest of the speakers. It's much more convenient to use a receiver which has 5.1/6.1/7.1 processing capabilities, and use the bass management feature to produce a good hearty subwoofer output for the sub's amp to fully exploit for some heart thumping bass.
    If you play just stereo material through your receiver, you won't get much bass at all (unless you want to expound on how you have the bass output signal connected to the subwoofer amp).
    I'm sure your dad's Denon 3300 will allow you the bass management features that will make your sub woof all night long.
    ------------------
    PatCave ; HT Pix ; Gear ; Sunosub I + III ; DVDs ; LDs
     
  14. ChristopherJ

    ChristopherJ Extra

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    Thank you for the input. Since my parents are on vacation, I can "borrow" it this week and try it out. I 'll let everyone know what difference it makes...darn, I hope this doesn't mean that I will have to go out and buy a new receiver. [​IMG]
     

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