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PA for Pubs and Small Outdoor Show

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  • PA for Pubs and Small Outdoor Show

    First, my apologies as I've been researching the board here and I understand this has been discussed at length. However, I still have questions as there is much to consider given how broad the knowledge base is here. That's a good thing in the end and I appreciate anyone who shares. OK, preface done, on with the show. . .

    Here's my gig. I play drums and sing lead with a group of guys I've been with in one configuration or the other for too long to mention. We're part-time musicians with other projects going, but this is my main rock band. The lineup is bass, drum, keys, lead guitar and electric mandolin. Generally, we play once a month at one of 3 small venues in our area and one small outdoor show averaging 50 people each. In the past year, we've picked up 2 additional, small outdoor shows each averaging from 300-500 folks seated within 50-75 yards of the band. We are getting offers for more shows this size in the area. The band is lead by myself and the keyboard player who has provided PA up to this point. Last show, my partner finally realized that the sound of the band using his dated equipment was not great. With that, I took it upon myself to take care of this issue.

    My new rig. I've purchased a rack where I've paired a Behringer XR16 digital mixer with an iNUKE 6000 watt, 4-channel amp. I understand I'm low-balling a bit and Behrigner is not looked upon fondly by professional engineers, but remember, we only play once a month and anything we use does not have to stand up to the rigors of the road. My intention is to work with our old passive EV Mains and JBL monitors to start with. The iNUKE will push the mains and our old Peavy head will push the monitors. I eventually plan to upgrade the mains and this may need to occur sooner than later, obviously.

    Given all that, I'm interested in info and opinions on what these speakers should be and the coverage I might expect. I'll be on a tight budget for these speakers and would like to stick with used JBL, Peavy, EV etc. at around $250-300 for each speaker. I'd like the additional speaker system to be versatile where some are used at the pubs and all are used at the outdoor shows. I'd prefer to stay away from heavy 2x15 cabinets as mains. I like the idea of using four 1x15s for the larger outdoor shows with two of the 1x15s doubling as monitors for the pub shows. But, I'd like to know more about options for the larger outdoor shows two 1x15s with two subs. I'm open to bridging and/or bi-amping to gain the head room need for the outdoor shows as well.

    Thanks again for any knowledge you impart.

    PS - Amp specs:
    4 channels = 1600w @ 2 ohms / 860 w @ 4 ohms and / 440 w @ 8 ohms.
    2 channels = (bridged) 3000w @ 4 ohms / 1600w @ 8 ohms

  • #2
    There is nothing small about playing for 300-500 outdoors. If my band is playing that size of gig we are using 4 3-way tops and at least 4 subwoofers. Your budget is unrealistic you would probably need to spend about 5k to do it. Your first mistake was buying a power amp instead of powered speakers.


    • #3
      To expand on ModulusMan's post -- you need WAY more power outdoors than indoors to achieve anywhere near the same SPLs. And you need 6dB more SPL every time you double the distance between a listener and a speaker to maintain the same SPL. To get 6dB SPL, you need 4 times the amplifier power.

      Okay, so how does this affect you. Let's say you are doing an outdoor show and the volume is acceptable 20 feet from the speakers and you have a 1000W speaker on each side of the stage. If you want the same experience 80 feet from the speakers - 4 times as far a way - you need 12dB more SPL, which translates to 16 times the amplifier power, or 16,000W a side (all else being equal).

      The other thing to remember is that if you're making it really damn loud up front, you need to make sure the speakers are up really high, so that you don't deafen the front row. But you also don't want the front row off-axis, or the sound will be bad. This might mean tipping the speakers, providing auxilliary coverage, etc. ........ doing some napkin math with a 120 degrees of coverage ..5 sq ft per person, 2500 sq ft for 500...let's assume a front row that is 37' feet wide, to seat 500 people, your back row will be 137 feet wide, the person at the back corner will be 58 feet from the stage, and the person in the back center will be 30 feet from the stage.

      When I do outdoor shows with my rock band, I rent a pair of Yorkville PS12Ps. These give acceptable loud rock sound for about 25 feet covering around 110 degrees. Folks who sit further than 25 feet from the stage get quieter music (lots of people want this, thank God). At 100 feet, these could be drowned out by a nearby transistor radio. I sell this system as covering 100-150 people outdoors at party volumes (not as loud as a concert). Going back with the math I ran above, I get 751 square feet of audience, which is 150 people. But we usually find a 200 square feet dance floor, which reduces capacity to 110 people. And this is "theatre-style seating". No guaranteed they will be packed that tight.

      The Yorkville PS12P is rated for 128dB SPL continuous at 1m. My furthest audience member (that wants it loud) is 25 feet away, which is 8m. 4m, 2m, 1m - three doublings means 18dB. So this system is able to deliver 110dB SPL or better throughout my audience, in theory. My goal is a minimum of 93dB SPL, so I have some headroom there.

      I'm kind of curious if some of those more experienced folks, like BillESC and Agedhorse will chime in with how they do capacity planning. I'm just a bar band guy.

      Last edited by wesg; 12-14-2017, 09:29 AM.
      Do daemons dream of electric sleep()?


      • #4
        I had considered that I may need to opt for powered mains and subs for outdoor use. The amp can then be dedicated to the monitors and I'm fine with that. After further research, that's the where I'm leaning.

        Wes, your situation sounds very similar to ours and I'm a bar band guy too. Not really a loud concert type situation, more of an outdoor party for local benefit like you said. After taking some Google Earth measurements, we only need to cover folks that are 50-60' away from the mains. If someone is sitting more than 50-60' away from the band and they can talk over the band? Sorry, but that's their choice, they've come to socialize and not really listen to the band. That would be half of the 500 max folks attending in range. That 250 figure is probably a good average of listeners to calculate from. With that and assuming the 110 deg coverage can be illustrated with a cone (50' height - 150' base) drawn stage center out towards the audience, we're looking at approximately an area of 3750 sq feet by my calculations. Not sure where I'm going with this or if I'm anywhere near accurate, just putting it out there.

        Thanks for the replies.


        • #5
          Do you live some place where you can rent FOH relatively easily? I really like pro rental houses, because not only do you get to "try before you buy", you can usually tell the guy the type of music and the venue and he can recommend something that will work for you.

          My napkin math suggests that the PS12Ps would do it for you, just barely, unless you need chest-thumping bass. In that case, $$$$$$$.

          I like PS12Ps for this application because they have a built-in multiband limiter, and so respond better than most to being run hard and incompetently. I find it hard to be competent at PA when I'm playing on stage ... So, the deal with the multiband limiter is that you can be inadvertently limiting the crap out of your kick drum, without affecting the vocals, even with no subwoofers. That is a REALLY big deal.

          The PS12Ps have a -3dB point of 45Hz, which is really low for a 12" speaker that makes 128dB SPL @1m continuous. Peak is 134, I think.

          If they weren't available, the next speakers I would be looking at are the JBL PRX612Ms. These are about as loud, but are down 10dB at 50Hz.....you will have quite a bit less bass unless you also buy subwoofers. In which case, the PRX718S-XLF is tough to beat. The 612M + 718S-XLF will sound better than the PS12P.

          QSC K12, KW181 is another such pairing.

          But remember, none of these are in the "pro provider doing 500 people" category. But I would use them for my bar band in a park as described. I have also used JBL PRX515s on sticks with a pair of center-clustered 618Ss outdoors for a crowd like you've described.

          What are you running right now, anyhow?

          Pro-am tip: if you are doing sound outdoors and have multiple subs, run them center clustered to avoid power alley caused low frequency phasing effects.

          Do daemons dream of electric sleep()?