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Question about response curves

Discussion in 'Home Cinema Speakers' started by Howard0000, Oct 19, 2003.

  1. Howard0000

    Howard0000
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    I am wanting to create a frequency response curve of my subwoofer like many of you have done.
    How would I go about it using an analog SPL meter and Microsoft Excel?
    Do I just make a table with sinewave frequencies and measure the SPL for each one, like 35, 40, 45, etc Hz, and then plot the levels on a graph, or is it slightly more difficult?

    Thanks, I'm kind-of a newbie at this business! :suicide:
     
  2. Smurfin

    Smurfin
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    You've hit the nail on the head. You measure the db level at set frequencies, which are generally sinewaves that you can download from the net.

    http://www.snapbug.ws/bfd.htm <----- that site which shows how to set up a BFD has all the links in it that you need for both the excel spreadsheet (which will automatically adjust for SPL reading inaccuracies at given frequencies) and a site where you can download sinewaves.

    Just be careful when playing back sinewaves as they have been known to fry subwoofer drivers. I'd also suggest not bothering to even look at your subwoofer response if a. You can't move your subwoofer and b. if you're not prepared to buy a BFD and spend some time tweaking it!

    Ignorance is bliss, as the saying goes:)

    Cheers
    Matt

    PS I've recently invested in a BFD for my twin sub setup, I have an excellent frequency response and with other acoustic treatments my system sounds utterly amazing:)
     
  3. Howard0000

    Howard0000
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    I'm doing it out of interest mainly, and I can move it easily if need be.
    I've heard that there isn't much of a chance of frying drivers if you don't play the sinewaves too loudly...What sort of levels should I be using to make the response curve?
     
  4. dunkyboy

    dunkyboy
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    Yeah, don't worry about it too much for just plotting frequency response - if you keep the overall levels at around 70 - 80dB it won't be a problem. What you really shouldn't do unless you KNOW what you're doing is to test your sub's maximum output using sine wave test tones.........

    Dunc
     
  5. Howard0000

    Howard0000
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    No, the Fast And The Furious tests that for me! :D

    That film has an awful lot of bass..
     

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