Out-of-Phase

Discussion in 'Beginners, General Questions' started by Dave Schofield, Jan 29, 2004.

  1. Dave Schofield

    Dave Schofield Second Unit

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    Can anyone recommend a "tie-breaker" to test in/out of phase speaker connections? I have owned and used Sound & Vision's Home Theater Tune-Up for some time. Until yesterday, I thought I was set up correctly. However, I purchased a Memorex CD/DVD lens cleaner that had a series of audio tests on the disc. In going through the in/out of phase test, it clearly appears that I have a speaker out of phase. I've checked my connections and rechecked S&V and can't find the problem. Is there any chance that Memorex has it screwed up? Is there another way for me to check short of purchasing Avia?

    I've meant to clean up my cords for some time, maybe this will be the catalyst...

    Thanks!
     
  2. Vince Maskeeper

    Vince Maskeeper Producer

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    here's an easy test:

    Unplug the wire from your receiver, noting which part is plugged into neg and positive. Take a 9 volt, and tap the speaker cable against the battery in the same way (the part of the wire that was plugged into neg on the receiver tap to neg on the batter, the part that was originally pos- tap to pos on battery).

    If the speaker cone moves OUT physically on the speaker, then you have it correct. If it moves in, it is wrong. Test each speaker. If all are right, you have no problem.

    -Vince

    PS: doing this multiple times risks damaging the speaker, so try to do it only once or twice, and maybe have a buddy to watch the speaker for you to see if it comes in or out.
     
  3. Rick_Brown

    Rick_Brown Second Unit

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    Another test: place two speakers facing each other a few inches apart. Play music with lots of bass that is mixed in the center. In-phase you will hear way more bass.
     
  4. JasonMA

    JasonMA Stunt Coordinator

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    You can also use the THX optimizer on almost any THX certified DVD out there. If you don't own one then go to blockbuster and rent Finding Nemo or something.

    The optimizer has a series of test tones to check for phasing. My assumption is that the memorex CD probably has the tone mixed up. I would trust S&V over memorex anyday for a test like this.
     

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