FFT Response Curve: EMIT Tweeter Repair Diaphragm

Discussion in 'Infinity Loudspeakers' started by Bobbyd38, Aug 11, 2018 at 3:40 PM.

  1. Bobbyd38

    Bobbyd38 AK Subscriber Subscriber

    Messages:
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    Hi Folks,
    I recently developed a replacement Diaphragm for Blown Infinity EMIT Tweeters. For a direct comparison I did FFT measurements on 4 Tweeters; two Infinity EMIT’s, and two with the new Diaphragm. Test was performed in a custom made 1 Meter Anechoic chamber with a Mini-DSP UMIK-1 calibrated microphone using Audio Tools FFT Software. Pink Noise was used as an input signal and was powered by an Adcom 565 Amp and fed through an Infinity Kappa 8 crossover with all controls set flat. Here’s a Graph showing the 4 plots, as you can see they measure very close to the originals.
    FD59AA70-D02F-4B4D-AA16-7C50045C055E.jpeg 9C7421E4-DB0F-4410-B474-FCF70AF2BD85.jpeg 476C8A43-15FD-4238-AD23-684B5FB37C3A.jpeg
    9C39960C-0457-4D8F-A723-C0B77F396C8B.jpeg
     
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  2. pauljh

    pauljh Active Member

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    Aha! I had missed that piece of information, and so I take back what I said in the other thread about crossover frequencies. You should consider testing the driver without the crossover. And it would be very cool if you could generate FRD and ZMA files for EMITs
     
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  3. Bobbyd38

    Bobbyd38 AK Subscriber Subscriber

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    I ran them through the crossover to both simulate real world usage and I run the risk of damaging them without a Crossover.
     
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  4. pauljh

    pauljh Active Member

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    Location:
    San Francisco
    Since you have an anachoic box, you don’t need to test at 110dB SPL, you could probaby get good results at 80dB. Plus, if you didn’t go below 1,000Hz, you wouldn’t hurt anything. When I get a chance to test the two diaphragms I bought from you, I’ll run an impedance curve on an EMIT.
     
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  5. chef free

    chef free AK Subscriber Subscriber

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    Excellent! The curves are very close. Nice work!

    You sure do test them LOUD! Did you test them at lower levels? I'd like to see a graph at about 80dB, closer to my actual listening levels...
     
  6. Bobbyd38

    Bobbyd38 AK Subscriber Subscriber

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    Being totally honest I just got this App and quickly did some measurements. It wasn’t intuitive how to set a reference level, so those levels are probably not accurate. I’ll post some more results after Getting to know the software better.
     

     

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  7. 7.62

    7.62 Gearhead Subscriber

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    I'm just here to congratulate you on at least getting pretty damn close. I don't know anything about all the numbers, Q, F and all the other things and I know their important. Your doing it and that alone to me is impressive as hell.

    Unfortunately none of my emits are in bad shape and I have spares, I still may buy a few of yours just to have.

    Now, this is a different ball game here, and while they work and read 3.4-3.5 ohms, my eyes burn and my heart skips beats over these on looks alone. I tried to capture the raised traces and the driver as a whole.
    IMG_2203.JPG
    IMG_2204.JPG

    If you decide to tackle these, I'm in big time. I have at least 10. And I have a line on a guy that can fix these..BUT they are pricey, my cost to fix 10 @ $330 each....well you get the idea.

    If you can do these at a reasonable cost I'm a player, and I'm betting many others also.
     
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  8. Bobbyd38

    Bobbyd38 AK Subscriber Subscriber

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    I am working on an EMIM Diaphragm as we speak. And they will be affordable. Thanks for your interest and the compliments!
     
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  9. slimpikkins

    slimpikkins Super Member

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    Wow Bob you are a busy man. They look great, nice work!
     
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