Frequency Analyser

Discussion in 'Mixing' started by Greener, Jun 2, 2008.

  1. Greener

    Greener Guest

    I require I piece of hardware I don't know the name of.
    I want it to be able to take a measurement of the sound pressure level over a broad frequency. And display it in a graph, also handy to be able to send data to and from a laptop.
    I want to use this device in this manner.
    I will put a cd of known frequencies, or pink noise or whatever I need to into a stereo. And place this device around where a user would sit, get a reading of the room. Adjust eq's until spl is flat across as broad a spectrum as I can get.
    People don't trust an ear.

    /I've been trying to do this with a Behringer mic, using the known frequency magnitude response graph I should be able to extrapolate what actual spls are there... but the data is bullcrap and I have no way of generating a known spl in order to calibrate the mic. Matlab is a devil.

    Cheers in advance.
     
  2. MadMax

    MadMax Well-Known Member

    Joined:
    Mar 18, 2001
    Location:
    Sunny & warm NC
    Home Page:
    They're called Real Time Spectrum Analyzers...

    Here's a few;

    http://www.fullcompass.com/product/284624.html
    This is the model I own. It's decent, accurate and very portable. It's drawbacks are that it does not come with a rack mount kit and the ranges can actually be too narrow for mixed volume content.

    Acid 8Packs
    Heard some good things about the True... just be sure your A/D's a good high quality unit.

    and there's the perennial favorite of
    http://www.purebits.com/

    Sticking with hardware based...
    http://www2.rohde-schwarz.com/en/products/test_and_measurement/product_categories/spectrum_analysis/FMU36.html

    http://www.home.agilent.com/agilent/product.jspx?cc=US&lc=eng&nid=-536902959.536881891

    Assuming that's a bit of overkill...
    http://www.phonic.com/en/other/testers/paa3.html
     
  3. Greener

    Greener Guest

    Bonus.
    Owe you one.
     
  4. Greener

    Greener Guest

    Btw, your SA3051 does have a rack mount kit optional.
    http://www.fullcompass.com/search.php?search_simple=true&txtAll=rm-10
    Even.
     
  5. Thomas W. Bethel

    Thomas W. Bethel Distinguished Member

    Joined:
    Dec 12, 2001
    Location:
    Oberlin, OH
    Home Page:
    ALSO

    Acid 8Packs
     
  6. Greener

    Greener Guest

    Cheers for all the links guys.
    That Phonic Paa3 looks tasty.
    I would love to splash out for one of those big beasts but it really just seems like a good quality calibrated mic, preamp and D/A with handy switches.
    Maybe I can mix and match, get a calibrated mic and use my laptop to do the analysing. I will be researching further.
    Thanks once again.
     
  7. BobRogers

    BobRogers Well-Known Member

    Joined:
    Apr 4, 2006
    Location:
    Blacksburg, VA
    I'm considering using Matlab for this on a limited basis , so I'd be interested in what you are doing.

    I'm going to be teaching a course in partial differential equations next academic year, and I'm thinking about what software to use for visualization. I also do a bit of comparison of calculations to real data (using room acoustics as an example). It would be nice to do a bit of real time analysis with standard mathematical software. I'll probably use Mathematica, but a lot of our students use Matlab. I may not go beyond identifying room modes, but I'd like to know what you have done with Matlab.
     
  8. Greener

    Greener Guest

    I wouldn't be using Matlab in realtime. You probably could but my head would melt before I got output.
     
  9. Codemonkey

    Codemonkey Well-Known Member

    Joined:
    Dec 11, 2007
    Location:
    Scotland, UK
    There's a cheap version of Matlab. Can't remember the exact name but I'm sure it's only one letter off.
    Apparently it has 90% of the functionality for either dirt cheap or free.
     

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