Eq'ing multiple subs that are different

Discussion in 'Home Theater Projects' started by Shawn Solar, Aug 20, 2003.

  1. Shawn Solar

    Shawn Solar Supporting Actor

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    I was just mostly wondering what people experiences are with eq'ing and blending multiple subs. I have a BP1503 sub in a ported enclosure tuned to 20hz. I just finished my prototype av12 sealed sub(1.1cubes) I call it a prototype cause Its still nekid[​IMG] and I wanted to make sure I liked it which I do. I only built one but have another on the way(driver is staring at me now)

    So I plan to have two sealed av12's, one to each main speaker of my room and then the BP1503. I want to use all of them. Then I got the idea of instead of building an LT circuit for each av12 I has just going to cross the ported sub around 50hz. Or If anyone could help me design a hipass at around 30-40hz to take over as the sealed rolls off.

    Then Would I eq both sealed and then the ported or all three at the same time. Not sure cause there are so many ways of doin' it. I was going to run the sealed of the main pre-outs and keep the ported for lfe but though I should just use them all on the lfe.
     
  2. TimForman

    TimForman Supporting Actor

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    I'm running a sealed Tempest and a Shiva TL. I wasn't satisfied until I Eq'd them with all the speakers running. I crossed them both at 80 Hz. My towers are still running strong at 80 Hz so I was getting some serious bumps in that range. Practically seamless now. Some have stated that subs should be EQ'd separately but I didn't have much success doing that.
     
  3. Terry Montlick

    Terry Montlick Stunt Coordinator

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    Subs must always be EQed together. An RTA (or your ear) is not sensitive to absolute phase. But subwoofer phases combine, resulting in unpredictable reinforcement and cancellation at different frequencies.

    Regards,
    Terry
     
  4. Shawn Solar

    Shawn Solar Supporting Actor

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    Thanks Terry, Tim,

    That clears up one issue. Now about a lowpass filter for the sub. if I wanted to cross it over at the -3db of the sealed subs and a 12db octave rolloff. or should it be -18db rolloff match the 12db rolloff better. I would prefer an active lowpass. Anybody know if one could be built cheap and how?
     

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