PA Setup

Discussion in 'Location Recording' started by nashtalon, Jul 15, 2006.

  1. nashtalon

    nashtalon Guest

    Hi,

    I a newbie here and am hoping to pick a few brains. :D

    I'm in a country band and we're putting together a PA system. Everyone has some gear already.

    So far we have:

    - Allen and Heath MixWizard 16 channel input mixer (used for FOH and monitor mix)
    - 2 Peavey SP 2 2-Way 15" Speaker Cabinets
    - 2 Peavy 18" subs
    - Variety of sm57 and 58 mics
    - 100' snake
    - Outboard gear: a 2-channel dbx compresser and an dual 31 band eq
    - 4 Shure PSM200 in ear monitor systems (one for each member, drummer currently uses a powered wedge but is switching to PSM400. Also, we currently rehearse with the in ears).

    We're looking to use this setup for a variety of gigs, small clubs to small outdoor shows, such as on a deck or bar patio. The goal is to keep things simple and easy to setup and tear down. One thing is I do like to have the sound in stereo. I know a lot of folks say mono is fine but I simply prefer the sound of stereo. Budget is around $2K. My questions are:

    What would be a recommended brand of power amp(s) that are good quality but reasonable priced (but not cheap)?

    Would it be better to have say, two modest amps running in bridged mono (one for each channel) or a single, more robust amp running in stereo?

    What's the simplest way of micing the drums but still getting good sound (kick and snare and two overheads, for example)?

    Any other recommendations would be greatly appreciated.

    Thanks!
     
  2. tallrd

    tallrd Active Member

    "What would be a recommended brand of power amp(s) that are good quality but reasonable priced (but not cheap)?"

    QSC's RMX series and Yamaha's "P" series are both great for the money. QSC has a little better specs, but Yamaha's have some more features (build in crossovers for example).

    "Would it be better to have say, two modest amps running in bridged mono (one for each channel) or a single, more robust amp running in stereo?"

    Get 2 amps, and run them each in stereo. One for L/R tops and one for L/R subs. That way each box has it's own volume control, you run lower total harmonic distortion, and you aren't running the amps as hard.

    When you bridge amps/lower the impedence you are increasing the distortion by 10 fold or more, and the amp doesn't sound as clean. Keep in mind you need to match up output power of the amp the the program power rating of the amp (including factoring in the impedence). It's ususally a good rule of thumb to have 25% more power at the amp than what the speakers program power rating is. For example, if your speaker says 100W @ 8ohs program power, then you would be served well by feeding it 125W of power @ 8ohms. If you underpower your speakers, you will clip your amp and it will die prematurely, not to mention putting square waves (i.e. distortion) into the high frequency drivers of your top boxes. That blows them too. It's much harder to blow speakers by overpowering them. Think of it like octane ratings in gas. Too low an octane rating will cause problems quicker than too high.

    "What's the simplest way of micing the drums but still getting good sound (kick and snare and two overheads, for example)?"

    Unless you are playing outdoor shows, or large indoor shows, you will likely not need to mic the cymbals for live sound reiforcement applications. I would mic the kick and snare with short, floor-standing mic stands with booms, and then clip on tom mics. Sometimes you can even get away without miking the snare depending on your drummers dynamics.

    Feel free to email me if you have any more questions.

    In the meantime, I hope this is helpful.
     
  3. MadTiger3000

    MadTiger3000 Active Member

    Helpful for all.
    Excellent reply.
     
  4. nashtalon

    nashtalon Guest

    Thanks, man! Very insightful.

    So would two QSC RMX1450, with output of 280W/ch @ 8 ohms, be adequate, in the configuration you gave of one amp for the top cabs R/L and the second amp for the bottom R/L subs?
     
  5. moonbaby

    moonbaby Mmmmmm Well-Known Member

    That might be enough power for the top boxes, but subs are power-hungry, and they should be getting double that. In clean, cool power, not something that is barely able to provide it.
    There are reasons tha many sound companies bridge their power amps for the subs. Generating enough juice into a load that is more stable is certainly one of them. (2) 2-Ohm channels bridged together to drive a 4-Ohm sub will definitely have better chance of delivering the clean horsepower that low frequencies require over a single 4-Ohm channel of power.
    And, for what it's worth, I have used many different power amps over the years. I was Pat Quilter's first dealer in Florida, I beta-tested the famous Yamaha P2200/P2100 power amps back in the dark ages, I've suffered multiple burn-outs of Crests, I've yanked and tossed Carvers (and Carvins!)...I've NEVER had a Crown drop on me. EVER. Whether it was a DC-300 in my early days, a D75 in the studio, or a MacroTech on a 24-box outdoor show. There may be prettier amps, none tougher. And if you're on a tight budget, I hate to say it, but the ubiquitous (gulp!) Peavey CS800 is not too bad on subs. They certainly beat a LOT of the stuff from overseas these days. PEACE...
     

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