Wiring subwoofers out of phase ?

Discussion in 'Archived Threads 2001-2004' started by John Tompkins, Apr 4, 2002.

  1. John Tompkins

    John Tompkins Supporting Actor

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    I was wondering if wiring the positive/negative speaker cables backwards is the same thing as a 180 phase switch on the back of some subs ? The reason I ask is that I had two velodyne subs located in the back of my room and I found that with the phase switch set to 180 that I got better/louder bass. Now I have two subs without a phase switch and was wondering if wiring it backwards would be doing the same thing as the 180 phase switch on the velodynes ?

    Also since I have two side subs hooked up to my side speakers, that if I did wire the subs backwards for a 180 phase shift, would it also be a good idea to wire my side speakers backwards as to keep both the side subs and the two side speakers that they are hooked up to at the same phase ? they will be crossed over at 100 hz with my side subs..
     
  2. Chris PC

    Chris PC Producer

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    In each room and situation, only trying and testing/listening will let you know for sure. Ideally, you can put your subs together and leave them in phase, but thats a whole other thread and can of worms.....
    Opps, forgot yer main question, yeah, swapping the + and - does the exact same thing as switching the phase from 0 degrees to 180 degrees [​IMG]
     
  3. Joe Casey

    Joe Casey Stunt Coordinator

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    To answer your original question..

     
  4. John Tompkins

    John Tompkins Supporting Actor

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    Thanks Guys,

    Chris, There is a feature on the lex mc-1 called bass enhance. It requires subs to be placed to the sides of the listener. It then creates "stereo" bass by using an algorithm that shifts the phase of the left/ right signals. Thats why I dont have them in one corner. I also have a third sub for the lfe in another corner(front} so phase on the side subs is rather important I believe.
     
  5. AaronNWilson

    AaronNWilson Second Unit

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    What should you be listening for as you move the phase dial from 0 to 180?

    Aaron
     
  6. John Tompkins

    John Tompkins Supporting Actor

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    Aaron, which ever position on the phase switch that produces the loudest/tightest bass is what to listen for.
     
  7. Mark Guidry

    Mark Guidry Stunt Coordinator

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    John T can you use a PS meter to check this out??
     
  8. John Tompkins

    John Tompkins Supporting Actor

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    I used a radio shack meter and the 180 phase was 2~3 db higher then 0 phase position.
     
  9. Mark Guidry

    Mark Guidry Stunt Coordinator

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    Cool...so that is a sure fire way to see if it needs to be out of phase or not...right?[​IMG]
     

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