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PA question

Discussion in 'Miscellaneous [BG]' started by SomeGuy118, Mar 31, 2003.


  1. Right now my band has a cheap 80w PA, we are thinking about upgrading to a 250w system. Feedback has always been an issue with the old PA, we could never fully push it to its limits. So my question is, first of all, is it worth it to upgrade and how much of an improvement should we expect if we do upgrade?

    I hope that made sense, thanks in advance.
     
  2. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    When I do sound, I use a graphic equalier to get rid of feedback. I try to "tune" the PA and the foldback before the rest of the band arrive:-

    I push the volume of the mic up slowly until i hear the onset of feedback. Whatever note the feedback makes, I hum it to myself. I then try to identify which slider on the graphic is generating the feedback. If it's, for example, 2K reduce 2k on the eq. Then start the process again.

    Keep identifying the frequencies that are feeding one by one and zap them with the EQ. Eventually it will get to the stage where several frequencies will take off all at once. When this happens, you've done as much tuning as you can. But by this stage, you should have already created plenty of extra feedback-free volume.

    A 31 band EQ is perfect for this. I've even managed to get the job done with 15 band eq's.

    Mic placement can also go a long way to reducing feedback. Always put your speakers in front of the band. If the sound from the speakers gets into the mic, it will certainly cause feedback. Never have a mic pointing towards a speaker.

    Try this before deciding wether a PA upngrade is needed.
     
  3. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    If you're going to upgrade, you oughtta wait until you can get something in the 1000+ watt range. There are a number of 600x2-watt stereo boxes out there ... Yamaha, Peavey, Carvin, or better, Mackie. It'll save you from yet another upgrade next year.

    We've been running 1500 watts for our mains for the last 9 years, but I'd like to add another 3 kilowatts for headroom.

    You also might want to consider powered speakers like JBL EON G2's or Mackie SRM450's. We run Mackie SR 1530's at our smaller gigs and they're 500 watts a side. I drool over the Mackie SA 1232's at 1300 watts a side. You'll never have too much PA power.
     
  4. Munji is right. Upgrading from 80w to 250w is hardly upgrading at all. As with bass rigs, power = tone. The more power you have, the better the tone you will have. And the more power you have, the less eq-ing you have to do, and the less feedback you will incur. I use an 800w Yamaha powered mixer for cafe and other small gigs, and supplement it with a 2000w power amp for bigger gigs.
     
  5. Ok thanks for the advice, now for another question lets say we were to get a 1000w system what type of speakers must we get, do they also need to be 1000w to avoid blowing them out? Also when a speaker says its watts is that how much it puts out or how much it handles or both?
     
  6. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    yep you'll nedd speakers rated at 1000w or thereabouts. They don't have to be 1000w exactly. You can go a bit under, or you can go as high as you like.

    If a speaker is 1000w, that's how much is can handle on the way in. Though this is just a guide and is not bible. It's not as though it will blow the minute you send it 1001 watts.

    You may want to do a bit of research on "clipping" when you get a chance. If you understand what makes speakers blow, it goes a long way to making sure it doesn't happen.