PA Mains Dispersion / Coverage question

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by bobbymack, Feb 13, 2008.


  1. bobbymack

    bobbymack Supporting Member

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    Hey PA / Live Sound gurus:

    I'm smitten by a pair of compact EV 15in 2 ways, but they come in 2 different coverage patterns: 90 x 50 and 60 x 60. At first thought I was inclined to go for the wider 90 degree horizontal coverage, but the sales guy was plugging the 60x60s because of phase cancellation issues with the 90s in a lot of rooms.

    He felt for most small to medium rooms the 60s would sound better in front of the stage, with less off-axis dropouts. I'd always thought the dropouts were due to insufficient coverage angles rather than phase cancellation, but apparently no. He says the 60s pointed more or less straight out, with their audio "paths" crossing in the back of the room, would sound better than the 90s because those paths would cross closer to the stage and create more dropout / phase cancellation issues.

    Does the 60 x 60 argument make sense? Educate me.
    thx
     
  2. bobbymack

    bobbymack Supporting Member

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    Anybody?

    Is common sense 90 degree wide angle better than narrower 60 degree dispersion??
     
  3. Geetarpicker

    Geetarpicker Member

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    I'm not a live sound pro, but I've owned a big triamped JBL system and currently have a compact setup with some EV sx300 1x12 cabs that I'm really impressed with. IMHO a small 1x15 2 way speaker isn't going to sound all that good from the very back of the room anyway. So, that said maybe the wider coverage would be better? Heck the part of the audience that usually "cares" will be right up front anyway. Hows that for non technical?

    Hmm, after just checking my sx300s are rated as 65/65 degree.

    Maybe the best way is to hook them both up at the store in as big a room as they have and listen and judge for yourself.

    Does the dealer have both of these speakers in stock? I've found some stores love to sell what they specifically have in stock AT THE TIME, regardless of what you might really want or even request... Some are totally out to "make the sale" no matter what.
     
  4. bobbymack

    bobbymack Supporting Member

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    That's what I'm afraid of, they only have the 60s in stock, which I think may be designed for arraying in permanent installs. My gut was to go for the 90 degree / widest dispersion possible until he started in on the phase cancellation thing...

    I'm gonna call EV.
     
  5. walterw

    walterw Gold Supporting Member

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    overly wide top cab dispersion might also tend to spill back into vocal mics onstage if the cabs are the least bit angled in, causing feedback issues.

    (although my 80% horizontal yorkville e-15s do just fine for my band.)
     
  6. RonnyLee

    RonnyLee Member

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    I'n no sound tech, but I've been playing for 40 years. I'd go for the wider dispersion. And, yes, that kind of cab can sound very good at the back of the room.
     

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