Some guides to REW and acoustic measurement

Discussion in 'Official REW (Room EQ Wizard) Support Forum' started by John Mulcahy, Apr 14, 2017.

  1. Todd Anderson

    Todd Anderson News Editor / Reviewer/ Senior Admin
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  2. Parag Ingle

    Parag Ingle New Member

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    Hi


    I want to know How REW(Room Equalization Wizard) works.can you please share the block diagram of how the received(Log Sweep) audio processed and converted to IR(Impulse Respose).this is only for my educational curiosity.
     
    #3 Parag Ingle, Dec 11, 2018
    Last edited: Dec 11, 2018
  3. John Mulcahy

    John Mulcahy REW Author
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    See Swen Müller, Paulo Massarani, "Transfer Function Measurement Using Sweeps", JAES Volume 49 Issue 6 pp. 443-471, June 2001. An extended version of the paper is available at CiteSeerX.
     
  4. Parag Ingle

    Parag Ingle New Member

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    Hi

    I have read the document it is showing many of the measurement method(as below)
    and its comparison.which one of these REW uses

    1)Time Delay Spectrometry

    2)Dual Channel FFT Analysis

    3)Stepped Sine

    4)Maximum length sequences (MLS)

    5)Periodic Signals of length 2^N

    6)Non periodic sweeps
     
  5. John Mulcahy

    John Mulcahy REW Author
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    REW uses a log sweep.
     
  6. Parag Ingle

    Parag Ingle New Member

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    Non periodic sweeps? or Stepped Sine?
     
  7. John Mulcahy

    John Mulcahy REW Author
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    Stepped sine isn't a sweep. Log sweep is an example of a non-periodic sweep.
     
  8. DanDan

    DanDan Member

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  9. mikewellington

    mikewellington New Member

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    Hi - I am pretty sure I have everything connected okay. I am using the UMK-1 and a USB audio interface that is connected to my speakers. I have the UMIK-1 set as the input device loaded with its calibration file. I have the audio interface outputting a decent level to the speakers but I keep receiving the message "The soundcard did not provide any input data, please check that it is connected." Not sure why this is happening...... I am running Windows 10.
     
  10. John Mulcahy

    John Mulcahy REW Author
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    The cable in the back of the UMIK needs a very firm push to seat properly, that can cause problems sometimes. Beyond that probably best posting a screenshot of your REW soundcard preferences.
     
  11. mikewellington

    mikewellington New Member

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    Thanks John. I had tried that and also a reboot. Seems to have done the trick. It's been a while since I used REW and my UMIK-1. Just moved into a new studio so trying to get my head back into the software again. Is there a link on tis website to the basic read out settings - I remember being advised before but have forgotten.... Thanks again for your help.
     
  12. mikewellington

    mikewellington New Member

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    It's all coming back to me now. Made a couple of measurements 45 Hz-20,000 Hz with 1/6 smoothing. Looking good. Is there a place to post measurements on here to get feedback?
     
  13. Sal Caralucci

    Sal Caralucci New Member

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    This is my first post and I am probably putting it in the wrong place. I have used REW for about a year and a half but, not since I updated my Mac to Mojove in October 2017. I am not getting audio in. When I do a loop back to calibrate my Focusrite Scarlett 2i4, I get output level and set the trim to be just under distortion on the Focusrite but, am not getting level in the input in REW. I have both Input and Output settings set for the Focusrite. I am running REW 5.20 Beta 4 and Mac OS 10.14.2. I have installed REW 5.20 Beta 4 on Windows 10 which I run thru Parallels on the same Mac. Everything works perfectly. It appears that REW on the Mac does not receive audio in on any input. I have tested the onboard sound and a second Focusrite RED 4 Pre on the Mac and can not get anything. I have clicked on Levels and talked thru a microphone and see no levels. I have tested the Mac with other audio software like Sound Studio and have no problems getting sound in. I have uninstalled and deleted all prefs for REW and reinstalled and still no audio in.

    Ideas???
     

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    #14 Sal Caralucci, Jan 10, 2019
    Last edited: Jan 10, 2019
  14. EarlK

    EarlK Member

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    Try this ( click the pic for a link );

    [​IMG]

    :)
     
  15. John Mulcahy

    John Mulcahy REW Author
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    Aside from the privacy setting/clicking OK when the OS asks if REW can access the mic, choose actual inputs and outputs from the lists in the REW soundcard preferences rather than leaving them set as Default output and Default input.
     
  16. John Mulcahy

    John Mulcahy REW Author
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    Sure, just make a new topic in this forum.
     
  17. Sal Caralucci

    Sal Caralucci New Member

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    Thanks, problem resolved. It was setting microphone in the security and privacy setting system prefs that resolved the problem. I did not realize that applied to sound interfaces, I thought it only applied to the microphone on my laptop.
     

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    #18 Sal Caralucci, Jan 10, 2019
    Last edited: Jan 10, 2019
    EarlK likes this.

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