What wattage needed for a PA??

Discussion in 'Band Management [BG]' started by Steve Harris Is, Dec 28, 2005.

  1. Steve Harris Is

    Steve Harris Is

    Jul 4, 2005
    The singer in our band has an OLD PA that finally fried and we have so far used it to just run his vocals in a VERY small club setting so we don't have any real clue what we need for power to run the whole band.

    So, I went to GC today and a sound guy mentioned that if we buy a new PA we need a MINIMUM of 1000W for a PA/Mixer if we plan on having all the instruments go through it (even in a small club he claims 1000W is least needed). Any thoughts or real world experience on this? Any help would be much appreciated!
  2. Diggler


    Mar 3, 2005
    Western PA
    If you mic your drums you need at least 1000 W for the subs alone. We were going to go with a minimum amount but ended up spending more to get what's recommended.

    It's easier to get a good mix if you run everyone mainly through the PA and let the band members use their amps more as monitors.

    My setup:
    Crest CPX1500: One channel for monitors, one for mids/highs; our mid/highs are Yamaha S112V's on sticks.
    Crest CPX1500: We run this one bridged, putting out about 725W into each 400W RMS sub. Pair your subs for best results, don't set one on each side of the band. You can pick up about 3db of volume this way.

    It's about all we need for now, but we don't blast people's ears either. Our drummer is loud and it often just keeps up with him, even unmic'd.

    We run all of our speakers with double the RMS rated wattage. You have to watch your clip lights and listen to the speakers, and back off if they seem to be overdriven but it gives you cleaner, more efficient sound.

    Bigger doesn't mean you have to use it all, but you'll get a cleaner sound out of your system if it can idle along rather than pushing it to its limits. And it will last longer, too.

    Check out these forums:
    Scott's PA System Tutorial (the friendlier of the two)
    ProSoundWebs Lab Lounge Forums

    I bought my stuff off of ebay and saved hundreds of dollars. All my stuff was new or only used a few times.
  3. mwm70


    Oct 27, 2004
    He's right, I learned this first hand over the last year. Bass and drums suck up alot of power. 1000 watts will be the minimum, basically 115s on sticks. Subs will require more power. As stated above you will not use all of the power available but the power used will be done so efficiently.
  4. McHaven


    Mar 1, 2005
    my little garage band uses a 100 watt package. it does the job. But for on stage, we'd rather use our amps than PA (shaddup, you FOH sound guys, i hate DI'ing, leave me alone)
  5. georgestrings

    georgestrings Banned

    Nov 5, 2005
    1000 watt minimum sounds about right - we're using a QSC power amp @ 850/channel, and a Mackie 8 channel powered mixer at 600/channel with a submixer for the drums - and it's pretty bare bones, IMO(in fact, we need a 2nd power amp)... that's powering a pair of 18s, and a pair of 15/horn combos - and a pair of monitors... I also pick up a little of the bass "slack" with my rig, btw...

    - georgestrings
  6. Steve Harris Is

    Steve Harris Is

    Jul 4, 2005
    Thanks for the help, I'll check some of those other forums you mentioned too.
  7. Get more than you need. Because eventually you will need more, and then what?

    And everyone's right.... the drums and bass will eat up the watts FAST. If you are just running vocals and guitars through it, you can get away with less than 1000w but it's best for the mix, and for versatility to get the bigger system now.

    Plus, remember you will often run into situations where you can rent it's use out or take a cut of someone else's gig for using your cool PA system!
  8. Bassstud1

    Bassstud1 Supporting Member

    Sep 23, 2001
    LaPorte Indiana USA
    I played in a small R&B trio with a singer and we used 1000w on the low end and some times the amp would clip. More power is always nice. I would say that 1000 watts for a PA is a mimimal amount of power for a half way decent sound to drive the whole band. Good Luck

    Oh and nettor, maybe that's why you guys are only a garage band.

    My 2 cents.
  9. 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
    He's not far off. As someone else said, you need more if you're running subs (and you'll need to if your bass is going through the PA).

    My standard rig is two EAW JFX-590s connected to a QSC PLX 3402 (700 watts a side at 8, a little underpowered for those speakers, rated at 500 watts rms). Also two EAW SBX-220 subs, each with its own bridged PLX 2402, which is just about right for the subs, which are rated at 1,400 watts rms. The monitors are four Cerwin Vega 12-inch 2-ways, and I run them all off a single PLX 1602. This is a bit much for a small club, but just about right for a medium venue or small outdoor gig.

    You need something like 1,000 watts mostly for the headroom. That said, I've played plenty of small bar gigs through a Mackie 808s, which is 600 watts a side, and this was using only one side for mains and the other for monitors. The PA was used only for vocals, and all the instruments went through stage amps only. With that setup, I'd get some good quality 12-inch or 15-inch 2-ways for the mains. Mackie makes some pretty decent passive cabs. It can be done and still sound good.
  10. Passinwind

    Passinwind I Know Nothing Supporting Member

    You're just talking front of house power, right? What's the biggest club you're contemplating playing with your new system?

    I've mixed in quite a few smallish clubs. One somewhat workable rule of thumb is 10 watts per patron for front of house power, assuming you have reasonably sensitive speakers. That's hopelessly simplistic of course, but it gets across the idea that bodies absorb sound, and that the physical size or capacity of a club doesn't tell the whole story.

    If you possibly can swing it, renting a few systems with experienced operators would tell you more about what you actually need than all of us together ever can.
  11. Dkerwood


    Aug 5, 2005
    +1 on renting a system first.

    I'm slowly but surely building my PA from the ground up. It started out with an 8 channel mixer that I would plug in wherever I could find PA gear - including plugging into my guitar amp from time to time... Then I "upgraded" with an ancient 400W Peavey amp and 2 column speakers. The Peavey died, and so I picked up a cheap 900W amp and 2 500W 15 mains to supplement the system (yes, I know, hideously underpowered, but I didn't know that at the time... I thought 900 < 500x2, so I won't destroy the speakers... yeah... I know...).

    That died, and now I've got a 1500W amp driving the whole thing, plus a new(er) 20 channel board. No bass through the system yet (no subs really, although the column speakers handle a lot of bass), although we do put the kick in there - EQ'd appropriately, of course. I'm thinking our next gig I'll try putting some bass in the system - mainly the low-mids - to see if we can get the stage volume down (our bassist's amp is LOUD for just 300W).

    Consider this. In a minimum "pro" rig, you're going to need an amp for your mains (which can be run out of one channel), an amp for your subs (which can be run out of one channel if you have efficient subs, but if you're going to have two amps, it's best to devote one amp to your subs), and you're going to need one amp channel for every channel of monitors you want to send.

    Think this through. Say you've got 2 150W mains (weak), 2 200W subs (weaker), and 4 60W monitors (are we playing bluegrass?). You're still looking at 940W that you'll somehow have to cover, just to push these speakers - not even considering headroom.

    Also consider ohm ratings. Amps dish out 8 ohms a lot better than 2 ohms, but published ratings - ie my 900W amp - are usually talking about 4 ohms bridged. That means a "900W" amp is actually 450W per channel @ 4 ohms stereo, and something like 300W per channel @ 8 ohms stereo.

    So in short, the answer is yes. 1000 Watts is a good place to start.

    And just for the record, there is absolutely nothing wrong with just putting vocals through the PA and letting your amps do the job they were built for. There are many venues where it's not necessary to use PA support, although it is nice... but there are also venues where PA support would be inappropriate. I can't tell you how many times I've walked back to a sound board when amps are turned down as much as they can and still be used as monitors - and the guitar or bass channel is completely turned down.

    It does seem a shame to buy that huge 8x10 monster stack and only turn it up to "a little less than 1 on the knob"... Just so that the subs, which likely cost less than the speakers in your stack, can maul your tone (which is already slaughtered by having to turn it down so far) and AMPLIFY it out to the crowd... ah, but that's a topic for another thread.
  12. When our band got our P.A. (1200-watts) - we did a gig with it in a club (can't really describe what size...fairly average size - about 1-2000 people capacity) - and we had it peaking of full whack and you could barely hear it...luckily the place had a P.A. as well, but we needed at least 2.5k...probably safer if you're a working band to get a 5k+ rig then you'll be sorted for any size gig on the club circuit
  13. theshadow2001


    Jun 17, 2004
    Our band used to have a PA consisting of two JBL 18's and two 15's
    it was powered by a 1000 watt dynacord desk. I used to DI my bass to it. There was a passive crossover in the bins. It was an ok rig but it wasn't fantastic.Probably could of got more out of it if we powered the bins seperately. I don't think the speakers were being driven to their capacity. But the point is that inspite of it's downfalls it was still worked for us in alot of smaller venues. however we did find that we ran out power in one or two larger venues. Now we have a HK projector which is 3.6kW and its active so there no messing around with crossovers and poweramps which is nice. Although they weigh a ton but Im certainly a stronger lad because of it. We are considering getting another four subs for it though but that won't be for another year or so. But with that there's not a venue we've come across that we cant fill with sound.

    Our drummer has a HK actor rig which I think is great. It's capable of doing from small to largish venues and it sounds great as well. I've also listened to DB rig which was very nice with a 3 way crossover it was active as well. It was in around the same wattage as the actor. I would rate either of those PA's highly
  14. FR5


    Feb 12, 2004
    I don't pretend to know a lot about PA's, but I will never forget a phrase that I read somewhere and that has served me well over the years:

    "assume 10 watt per person (in the audience), or 5 watt per square meter"

    Rgds, Steven
  15. RicPlaya


    Apr 22, 2003
    Whitmoretucky MI
    Whatever you do make sure you pump 1.25-1.5 x the RMS of power into your speakers. I like the Yammie V series, best bang for the buck..they have Emminence drivers. I also like some of the Behrenger stuff for boards..you can get a good one for $450-500. Whatever you do make sure you get good amps that have good clean power.
  16. Dkerwood


    Aug 5, 2005
    It's always better to have too MUCH power than to have too little.
  17. Steve Harris Is

    Steve Harris Is

    Jul 4, 2005
    Thanks for all the help guys...our first gig won't be until March and it will be about 75 people-ish so I'll check back then. Advice has beeh helpful though, thanks much.
  18. 5string


    May 5, 2003
    Hanover PA
    I have this

    Mackie 2600 - subs
    Mackie 1400 - mids
    Peavey 900 - highs
    Mackie 800 - monitors

    Plenty of head-room, never feeds and the amps don't break a sweat.