bass cancellation

Discussion in 'Archived Threads 2001-2004' started by JulianBrock, Sep 25, 2002.

  1. JulianBrock

    JulianBrock Extra

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    I recieved my Tempest and finished my box... but for some reason.. I felt the bass was lacking. It sounded great if you put your ear near the sub. I moved the sub into a cubby hole in my room (hard to explain but I can take pics)and the bass increased 10 fold. I don't have any leaks. When I push down on the speaker.. it is very slow to release and I fed a 10hz tone into it to hear any leaks from the baffle. Anyone have any problems with room cancellation? Does this even sound like bass cancellation? I have a 230l box with 64oz of poly on a PE 250watt amp. If I can't get it to bass due to cancellations... is my only other route building another Tempest? Below is my install process... I think I have all other bases covered. I even used a battery to verify that the + and - are marked correctly on the speaker.
    I have the + linked to the + on both vc as well as the -. I then have the + and - off the amp going to one of the vc.
    I also disconnected my mains (alesis monitor 1's) just in case those were cancelling.
    http://www.txraves.org/~magnetik/diy/Page.html
    Oh.. also.. how long does it take to breakin the Tempest? also.. will it be real noticeable once it does break in?
    Thanks in advance!
    Julian Brock
     
  2. Richard Greene

    Richard Greene Stunt Coordinator

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    I built a 230 liter sealed Tempest tube subwoofer with
    8 lbs. polyfil inside last year.

    The driver took about ten minutes to break in while
    playing loud bass-heavy music that stroked the cone to roughly 1/2 xmax -- efficiency increased about 6db over that 10 minute period.

    You can always measure a subwoofer by placing a mic or your ears near the cone. Whjt you hear at your listening position dependsmainly on the room --/-10dB is typical when playing a slow sine wave sweep test tone measured at your listening seat (for the Tempest or any other driver)
     
  3. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    Check the volume level on the receiver and on the subwoofer amp.

    Bass cancellation occurs more frequency specific. A room will have certain bass waves that will have cancellations while other frequencies will be amplified.

    If the entire spectrum is cancled out then it is similar to running the tempest with no enclosure at all. The front/back sound cancels eachother out while it is loud when you put your ear to the driver.

    I too noticed minimal bass when the sub was in the middle of my room. It was until I placed the sub in a corner where it gained between 3 and 6db in output.

    Breaking in a tempest should happen on your first bass song. I heard that if you ran your finger around the surround it's broken in.
     
  4. JulianBrock

    JulianBrock Extra

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    Luckily.. I found a good spot in the room for it.
    check this out..
    How's this for room gain? [​IMG]
    http://txraves.org/~magnetik/diy/IMG_0550.jpg
    The driver finally either got broke in.. or me moving it to the opposite side of the room did it.
    I wish I could have kept it in the cubby hole.. the bass was insane when standing in the small room! But.. the bass was pretty much contained in the room..
    This thing is too big to move even a few inches..
    I eventually moved it to the right of my setup instead of the left.. I think the cubby hole caused the cancellations which is directly to the left of my setup.
    overall.. I am very pleased.. the quality of the bass is incredible.
    I completed the website of the total process... if anyone wants to check it out what I had to go through.
    http://www.txraves.org/~magnetik/diy/Page.html
    Julian Brock
     
  5. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    lol, that's pretty cool.

    There'd probably be a lot of bass if you put the sub in the corner of the cubby and had the listening position there too.
     

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