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Phase Correction.

Discussion in 'Recording' started by nihility0000, Mar 14, 2006.

  1. nihility0000

    nihility0000 Guest

    Hello all,
    I recently read (don’t ask where) that if you invert the polarity of an xlr cable, this will help in correcting phase issues. Is this true? If it is, how would I go about performing this procedure, though I am a little reluctant to start cutting up one of my cables.
    Also, is the phase invert option in my DAW (Sonar 4 PE) accurate?
  2. Zoro

    Zoro Guest

    I know that most DAW's has a phase inverter, for instance in cubase you go to rigth click and process a phase inversion and buala, I don't know about Sonar but you should try to find this otpion berofe cutting into cables, specially if they are expensive and are AES/EBU aproved. :)

    Good Luck.

  3. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    nihility0000, the phase issues that you are speaking of are generally not the cause of miswired microphone cables. Phasing issues occur whenever there is more than 1 microphone in use! If you have 2 microphones anywhere within the proximity of a sound source, both microphones will pick up the sound source with an extremely small time differential that occurs from the sound source striking the capsule of the 2 microphones at different points in time.

    Miswired microphone cables can cause huge phase cancellations between 2 different microphones picking up the same sound source and should not be confused with multi-microphone timing problems. DO NOT REWIRE YOUR MICROPHONE CABLES!

    Many consoles along with most software allow for phase reversal or phase inversion so there is no real need to change microphone cables at all! If you want to check microphone cables for improper wiring, you can do so with a ohm meter or a specific cable testing device made by numerous manufacturers. For most microphone cables that utilize 3 pin XLR connectors, pin 1 is always Shield/ground. Pin 2 is generally designated as " + " high and pin 3 is generally designated as " - " or low.

    If you are miking a drum kit and are using 2 microphones on the snare drum. 1 on top and 1 on the bottom, you will want to invert the phase for the microphones on the bottom. If you want a tighter and harder bass drums sound, invert or flip the phase of the bass drum microphone. Phase inversion has other applications for tracking and mixing, microphone inputs and line inputs, speakers, etc. but is generally not something you want to screw around with since an out of phase stereo recording can sound extremely wide but will completely disappear in mono. Something I've heard happening much too often.

    I'm phasing out!
    Ms. Remy Ann David
  4. nihility0000

    nihility0000 Guest

    thank you remy, cleared that up for me. this is the reason i wanted to post it here before cutting into my cables. once again, something on the internet and my local guitar center pro audio tech has steered me wrong.
    he told me that i should keep an inverted XLR cable around the studio, because i do not have a pre with a phase invert option.
    i mostly get phase issues when micing guitar cabs. besides the phase invert option on my DAW, is there any other way of fixing this problem. maybe with mic placement?
    thanks again.
  5. RemyRAD

    RemyRAD Guest

    Sep 26, 2005
    Having a single " Marked" phase reversed microphone cable is probably not a bad idea in lieu of a phase flip switch but only if you need to do that. These days, most all of this can be accomplished within software and is generally not hardware dependent anymore except for a live performance situation.

    If you are miking an amplifier cabinet with more than one microphone and/or taking a direct DI and a microphone, say on your guitar or bass, there will naturally be minute time differences. This is not a 180° situation as a switch or a cable provides for. This is something that you can correct for within multitrack software as these time delays are generally from micro-seconds to milli-seconds.

    To "time align" your minor timing issues, you would need to zoom way in on those 2 tracks in question and delay one (generally the DI which always " sounds" before the microphone does) so as to align it perfectly with its sister track and/or tracks. Depending on your software this is usually accomplished with either a left or right click plus drag. Once corrected, you'll want to save your project that way. You only need to make these corrections if you feel that the "phasing" problems are making a sonic impact on your sound and should not be done just to do it. All phasing issues are not necessarily bad but help to give us our cues for time, space and distance. There will always be phasing issues when you use more than one microphone, ALWAYS.

    There have been many posts on this forum and others about the best way to " focus" a multi-microphone drum mix, for instance. Generally a good way to discover if you are having phased issues is to monitor in mono. Or you can solo numerous input sources and if you find that bass response decreases between your sources under scrutiny, you may need to reposition microphones and/or " Flip phase" between the 2 sources until bass response increases instead of decreases. That is usually a good sign of good phasing when bass multiplies as opposed to cancels.

    My waistline has multiplied and that's not good!
    Ms. Remy Ann David
  6. dwoz

    dwoz Guest

    This is an oxymoron.

    Phasing issues such as you've described are TIME DOMAIN issues. FLipping the polarity of the mic cable will only change the frequencies affected by the phase problem. You might get lucky and find that a flipped polarity signal sounds better...but it isn't really solving the problem.

    remyRad is giving you some good poop here.

  7. nihility0000

    nihility0000 Guest

    i have figured this out.

    i have also figured out that my phase problems can not be solved by swapping polarities.

    there is a great tutorial on phase and polarity at http://www.prosoundweb.com
    (its kind of hard to digest but i learned alot)
  8. dwoz

    dwoz Guest

    I absolutely, completely swear on a stack of bibles and under penalty of perjury that I DID NOT SET THIS UP. It just happened on its own.


  9. nihility0000

    nihility0000 Guest

    set what up?
  10. dwoz

    dwoz Guest




    (I'm a moderator at prosoundweb...)
  11. Kev

    Kev Well-Known Member

    Nov 13, 2001
    we believe you
  12. nihility0000

    nihility0000 Guest

    ha ha ha :lol:
    great site

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