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sonosub performance Q's

Discussion in 'Archived Threads 2001-2004' started by Jayson Y, Mar 31, 2001.

  1. Jayson Y

    Jayson Y Auditioning

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    My friend and I just finished the first of two subs we've been working on. Its 14.3cuft,62" internal hieght and 24" dia tube w/tempest driver and AVA250 for power. The port is 10" dia and 35.5" long(17hz tune). We have a 3/4" MDF doubled for top and btm caps, one in the tube the other outside with 1/2" over hanging. Also have the sock material tucked inside top and btm. It's all caulked on the inside but I think it's leaking, bad noises coming from the driver, REALLY BAD!!
    Its diffently bottoming out. the amps dial is at about 3/4 power and my xover is set to 60hz @ the reciever(outlaw 1050)and set to 180hz on the AVA250.
    The only material we had handy @ test time was Toy Story 2 and it was going nuts on the opening buzz fly in.
    HELP!! I remember a thread that talked about leak checking but can't seem to find it.
     
  2. Mark Wylie

    Mark Wylie Auditioning

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    I'll be starting my sonotube project this week after spending a couple of monthe doing research. I'm wondering if the 10" port is the problem. There is a rule of thumb that states that the port volume shouldn't exceed a certian level of the volume of the driver ... or something like that. Sorry I can't be more specific. My gut feeling however is that the port is just too wide.
    Mark
     
  3. Jayson Y

    Jayson Y Auditioning

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    We actually modeled this after Jeremy Santos twin towers found here on the forum!!
     
  4. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    >>>My friend and I just finished the first of two subs we've been working on. Its 14.3cuft,62" internal hieght and 24" dia tube w/tempest driver and AVA250 for power. The port is 10" dia and 35.5" long(17hz tune). We have a 3/4" MDF doubled for top and btm caps, one in the tube the other outside with 1/2" over hanging. Also have the sock material tucked inside top and btm. It's all caulked on the inside but I think it's leaking, bad noises coming from the driver, REALLY BAD!!
    Its diffently bottoming out. the amps dial is at about 3/4 power and my xover is set to 60hz @ the reciever(outlaw 1050)and set to 180hz on the AVA250.
    The only material we had handy @ test time was Toy Story 2 and it was going nuts on the opening buzz fly in.
    HELP!! I remember a thread that talked about leak checking but can't seem to find it.
     
  5. Jayson Y

    Jayson Y Auditioning

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    How big is the room?
    The room is 12'wide x 23' long w/8' ceiling.
    how loud is the sub playing when it *knocks*?
    do you have anyway of running a testone at the tuning point of the sub? --------------------------------------------------------------------------------
    I did make an adjustment to the AVA250 xover It's now set @ about 100hz and the receiver is still @ 60hz. the receiver out is still @ -10db but theAVA250 volume is now @ 1/3%.
    Using Avia GTHT,I Set the spl level @ 90db with 100hz signal and let disc play. The sub spl output was
    100hz-80hz 90db
    80hz-60hz 100db
    60hz-45hz 106db
    45hz-30hz 108db
    30hz-25hz 98db
    25hz-20hz 93db
    these were taken about 1-3" from the dust cap and are uncorrected #'s for the RS meter(can't find my correction value cheat sheet wife cleaned the desk!!)
    I know this is not the correct way to do a test but was the only thing I could come up with @ the moment. Will try to down load something and burn a copy later!!
    Could the plate amp be clipping with TS2? I'm home alone this morning and was able to try Gladitor,and Twister after making the adjustments to the xover and volume control no problems with them even @ very high levels, was getting 126db from the sub @ edge of tube near the floor during The Battle Of Cartage(Gladitor) and 1960 Prologue(Twister) and 110 db from setting area. TS2 still had some trouble but not nearly as bad as before.
     
  6. Chris Hoppe

    Chris Hoppe Stunt Coordinator

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    Well, I've had some experience with very large ported boxes such as the one you've built. In general, big boxes give better performance. Lower lows, less distortion and louder at that too!
    A couple things to keep in mind; A big box usually requires much less power for a given SPL than a small one. Another thing is that a large ported box is more prone to overexcursion than a small one, due to the higher compliance of the volume of air inside the cabinet. It is therefore [​IMG]CRUCIAL [​IMG] to use a subsonic filter in this application! I can't stress this enough! (there are no more UBB functions to exploit)
    As you may know, in a ported box, the woofer behaves as if it were operating in free air below the box's tuning frequency.
    Without a subsonic filter, your woofer's just a' flappin in the breeze, expecially in a large box with a low tuning.
    Good luck!
     
  7. Jayson Y

    Jayson Y Auditioning

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    Okay a subsonic filter it is!! What does this filter do? I'm assuming it filters out the signals below my tune? And were can I get one?
    Thanks for all the help guys,
    Jayson
     

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