IB Subwoofer setup done!

Discussion in 'Home Theater Projects' started by MichaelDa, Oct 7, 2003.

  1. MichaelDa

    MichaelDa Auditioning

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  2. Owen Bartley

    Owen Bartley Second Unit

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    Nice work, the project turned out really good! How does it all sound? Especially the IB??
     
  3. Chris White

    Chris White Second Unit

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    Very nicely done Michael, and a great webpage too. I've added a link to your new page to my own DIY projects webpage.

    DIY Projects
     
  4. MichaelDa

    MichaelDa Auditioning

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    Thanks!

    The system sounds great! I'm still working on tuning the sub, and am learning so any help would be *greatly* appreciated! I have a BFD installed, but it is set at factory default with no filters running. I took some initial readings last night. I used white noise to set the level at 80dB (is this correct?) and then ran the test from the listening position (meter on a tripod) using the NCH tone generator. Here's my results for that test:

    HzdB
    ----------
    1659
    1860
    2067
    2271.5
    2571.5
    2878
    3284
    3679
    4083
    4582
    5078
    5685
    6389
    7197
    8089.5

    I need to read up on the BFD before moving forward... any suggestions?

    Thanks for the link, Chris! I'll reciprocate once I add more to my site [​IMG]
     
  5. Chris White

    Chris White Second Unit

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    You should probably take more readings in case you're missing some bumps (at 60hz for example). Based on what you have here, your response is reasonably smooth with an average ajusted SPL (I assume the numbers you reported are un-adjusted) of 82db with a standard deviation of 8.62. If you drop the two lowest frequencies (since you can't do anything about that dip), the un-adjusted SPL becomes 84.3db with a standard deviation of 6.59. As you can see, you're average SPL as about 9db too hot.

    A 6db filter at 63 and 80 hz, plus a 14db filter at 71 hz would drop the average to 82.3 with a standard deviation of 3.9. Of course, the change won't be exactly that, because every filter affects harmonic frequencies.

    There are a couple of other hi-freq filters you can set, but I'll have to look them up tonight, I don't have that here in the office.
     
  6. ThomasW

    ThomasW Cinematographer

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    Michael

    Follow the instruction on Sonnie Parkers Bugsnap site.

    Start by making a fairly wide band filter to flatten (cut) the big hump at 71Hz. That should also help smooth things out from 50Hz to 80Hz
     

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