Calculating speaker sensitivity?

Discussion in 'Home Theater Projects' started by MarkRoberts, Aug 9, 2004.

  1. MarkRoberts

    MarkRoberts Stunt Coordinator

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    Is there a way of determining the sensitivity without taking 1w/1 meter readings? I notice that manufacturers seem to achieve quite high results but similar diy projects produce lower results, why? Most manufacturers end up with 90db+ and they are 8 ohm nominal. The only (that I have seen) high diy projects are either 4 ohm nom. or use horn tweeters. Could some of the guru's out there shed some light on the subject. Thanks, Mark
     
  2. ThomasW

    ThomasW Cinematographer

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    There's really no short answer to this.

    Mfgr's will usually chose a specific frequency to test, that provides the highest SPL level. Frequently that frequency has no bearing on the passband where the driver will be used. For example, testing a 12" woofer at 1kHz often gives the highest sensitivity reading. But who ever uses a 12" driver at 1kHz?

    Also some mfgr's 'fudge' their sensitivity ratings. :wink:

    So take the published specs at face value, and do your own testing/measurements when creating a design.
     
  3. MarkRoberts

    MarkRoberts Stunt Coordinator

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    I was hoping there was a way to ballpark it while in the designing process. Before the commiting to using specific drivers. I am sure there are allot of variables to this x-over design and t/s parameters etc. just wondering. Does that x-over pro/bass box pro software do any "estimated" response? Or any recommended x-over design software?
     
  4. ThomasW

    ThomasW Cinematographer

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    The XO design programs take whatever info you put into them and create an predicted FR plot.

    When designing a new system, one should take their own measurements of the drivers placed in the baffle where they are going to be used. During this time it's a good idea to check sensitivity.
     
  5. MarkRoberts

    MarkRoberts Stunt Coordinator

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    Thanks for the help Thomas. I was hoping there was a way to do it without the cost of the drivers upfront, but oh well. On a seperate (cloning) note I have finished taking measurements of the kestrel 2 TL from a pic. So I now have my cut list. I noticed that several of the pieces are angle mounted. Is there a way to determine what angles they are mounted at? Is it a simple matter of using a protractor? Thanks again for your help.
     
  6. ThomasW

    ThomasW Cinematographer

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    Yes just print out the picture, then use a copier to enlarge it if necessary.

    If you're copying their design; and you know the drivers and the XO, you don't need to measure or model anything
     

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