Loudest speaker for gymnasium pep rally

Discussion in 'Live Sound [BG]' started by Sturg, Sep 13, 2019.

  1. Sturg


    Nov 29, 2013
    Used my QSC-K12.2 with a microphone today at a high school pep rally. Volume was ok, but need something MUCH LOUDER, in order to be heard over pep band, noisy kids, etc. What do you recommend?
    Is there anything out there that is RIDICULOUSLY LOUD, and would work well in this situation?
  2. walterw

    walterw Supportive Fender Commercial User

    Feb 20, 2009
    the more money you spend and the more powerful speakers you get the louder they will be
  3. DirtDog


    Jun 7, 2002
    The Deep North
    The gymnasium’s acoustics are going to work against you.

    A more powerful speaker will just create more cacophony.
  4. Stumbo

    Stumbo Guest

    Feb 11, 2008
    You're in an echo chamber.

    IME, More volume=more echo.

    Gotta work the eq. to cut through.

    Less bass, more mids/upper mids.

    Try playing with a pick.

    Add a HPF to your signal chain!
    Last edited: Sep 14, 2019
    pellomoco14, chupacerveza and JCooper like this.
  5. hbarcat

    hbarcat Supporting Member

    Aug 24, 2006
    Rochelle, Illinois
    A gymnasium is literally the worst acoustic environment you could play in. You could certainly get an amp and speakers with a lot more volume but it will just be a louder version of the boomy, echoing noise you've already experienced.
  6. musicman7722


    Feb 12, 2007
    Hampton NH
    That is a heck of good speaker. Try using a small mixer. Plug the mike into the mixer and the mixer of course into the QSC. Set the speaker for the default DSP setting.

    Now you can get more gain into the speaker using the mixer AND you can roll off the low end to help reduce the rumble.

    Finally put the speaker up in the air try using a speaker pole and get it at least 6' up.

    Good luck
    chupacerveza likes this.
  7. jimfist

    jimfist "Cling tenaciously to my buttocks!"

    Mar 28, 2011
    Boston, MA (USA)
    in these situations, I'm a fan of using multiple speakers for coverage, rather than bludgeoning the space with a single point-source speaker. Question #1 is: where is this single speaker located? Is placed in order to cover the listening area equally? If not, and some of the audience is close to the speaker with others far away, then you'll be cranking to accommodate the furthest reaches while melting the faces of those close by.

    An alternative thought: 3 or 4 very modest-but-adequate powered speakers ($250 ea+/-) on tripods will do better in these types of environments than putting all eggs in one basket, spending well upwards of $1000 on a single, high powered speaker.

    This is a matter of covering the area adequately with intelligibility more than anything else. Perhaps other scenarios would be better suited to the "loudest speaker I can get" train of thought, but perhaps IMHO not this one.
    Wasnex, chupacerveza and HolmeBass like this.
  8. john m

    john m Supporting Member

    Jan 15, 2006
    Mic in front of a DB?
    Start with a pick up system.
    chupacerveza likes this.
  9. Were you miking a bass?
    jimfist and chupacerveza like this.
  10. Stumbo

    Stumbo Guest

    Feb 11, 2008
    Mic for PA? Upright?
    Last edited: Sep 15, 2019
    jimfist likes this.
  11. I played a gig at a school gym. The amp was out in front of me, and I would hear it bounce off the back wall and come right back to me 1/2 second (or whatever delay) later - and hear it louder than I heard my cab. Even standing with my cab behind me - pointed at my knees, the reflected sound hit my ears just as loud as the cab behind me. Had to raise the cab up and lower the volume. Drove me nuts.

    You can try pointing your cab at an angle, but it’s still going to bounce around and create a mess of noise.
  12. Just get out of the gymnasium or cover the walls and ceiling with yoga mats. There will be no sonic space or clarity to the balance. In the gym, uptempo tunes will be mush. The good folks that organized the affair could not care less. The cafeteria may be an improvent. Teachers lounge is your best bet.
    Last edited: Sep 14, 2019
  13. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    How were you micing a bass guitar?

    What kind of mic and what kind of bass?
  14. Wasnex


    Dec 25, 2011

    This is the answer. Ideally you need speakers with very tight pattern control over their entire bandwidth, so you can aim the sound on the audience like a beam coming out of a flashlight. The idea is for the audience to hear primarily direct sound coming from the speakers. Unfortunately real world speakers generally become less and less directional as the frequency decreases. The lowest frequencies are basically omnidirectional and shoot out in all directions.

    Since a gym is large, and has a lot of flat surfaces and very little acoustic treatment, low frequencies tend to bounce around for a long time and create what is called a diffuse field. A diffuse field basically means the sound is moving in all directions randomly and the SPL is uniform throughout the room. This distance in which direct sound is equal to the reverberant sound is called the critical distance. In order to increase the critical distance you need to keep as much off the sound of the floor, ceiling, and walls as possible.

    The tools you have are speaker aiming and possibly an HPF. The K12.2 has a built in tilt adapter, so get the speaker up high and then tilt it to aim down into the audience. Next run the HPF up as high as you can without gutting the sound source. Remember the speaker has better pattern control at higher frequencies, so the idea is to cut the lower frequencies that are unnecessary and shooting off at wider dispersion angles to bounce off reflective surfaces and feed the diffuse field. If you are using the mic for vocals I would start with an HPF up around 180hz and increase it until the lowest range of the vocals starts to thin out. Depending upon the vocalist, you may run the HPF up over 300hz, or if the vocalist is a baritone you may have to drop the frequency a bit. In my experience, it's extremely rare to need to run the HPF below 180hz though.

    FYI, the dispersion of the K12.2 is listed as 75 degrees, so use this for course aiming of the cab by eye, and then use your ears to confirm the aiming. Obviously 75 degrees is not a wide enough dispersion pattern to cover gym full of people. Ideally, you would have a row of speakers run across the face of the intended audience. By running multiple speakers closer to the audience, you can actually turn the level down so less energy is fed into the diffuse field. The minimum distance from the audience and spacing between the speakers would be determined by the 75 degree dispersion pattern.

    Of course I realize cost is a prohibitive factor, but I think your best best is to buy another K12.2
    Stumbo likes this.
  15. Two QSC-K12.2 :)
  16. Is it to be used with Metal?
    walterw likes this.
  17. pellomoco14


    Mar 2, 2017
    Newport, OR
    I remember those Friday afternoons. For a while is was such a problem. I would rather be in class. The best I had access to was the schools crate 1x15 tweetered combo with a 10 band graphic eq. I boosted around 600hz-3500hz. and cut practically everything else almost as much as possible either 12 or 16 db. (as suggested above). I laid the amp on it's back and propped it up a few degrees for ventilation. The dusty rafters and flags helped trap the echos especially with full bleachers.
    DJ Bebop likes this.
  18. jimfist

    jimfist "Cling tenaciously to my buttocks!"

    Mar 28, 2011
    Boston, MA (USA)
    OP, please clarify...are we assuming the QSC is being used with a MIC plugged into it for speech? Or are you talking about bass (guitar) amplification?
    musicman7722 likes this.
  19. musicman7722


    Feb 12, 2007
    Hampton NH
    That is my assumption as well, vocal not a band setting.
    DJ Bebop likes this.
  20. DWBass

    DWBass The Funkfather

    This. I did a gig in a gym and sound company had a full system in there. Way overkill. Loud as hell. And way to reverby. I told him to turn off the subs and bring the volume way down.

    Maybe just add a second speaker. Aren't those QSC's supposed to be the bees knees?
    DJ Bebop likes this.