Subs against wall in a cornered stage?

Discussion in 'Live Sound [BG]' started by hopturn, Nov 10, 2012.


  1. hopturn

    hopturn

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    Hello...I've read a million posts and am still confused. 3 of my band regular gigs are on low one foot stages that are in the corners of rooms. The dance floor is right in front of the stage. Long bars are on the other side of each room drummer is center stage against back wall, guitar on hi-hat side, bass on ride side, sax/keys/vox guy in front. I'm bass, and I put my amp into the back corner, so that I have a wall to my side and behind me.

    Now, our QSC powered mains are up on stands offstage in front...no room onstage anyway. All three stages are kinda small, but the rooms are 300-450 capacity, high ceilings...old buildings with brick inner walls. Where should I put the subs? Against the wall, coupled, in front of me? Or in front of the guitar player, which would really put them in the center of the room because of the nature of the stage? Really can't center-cluster them.

    So: better coupled flat against the wall facing the crowd on my side of the stage in the front beside the left main box on the floor?
    Or: better coupled beside the front right main on the floor (looking at the stage) but against no walls?

    I'm new to owning a PA, obviously.
     
  2. uhdinator

    uhdinator

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    3 1/2 feet from a wall/boundary cancels
    80hz. 7 feet cancels 40hz.

    So if you can't put subs closer than 3 feet from walls, put them side by side centered and 7 feet or more from walls. Don't set them on hollow stages. I use auralex gramma pads under mine if they are on a type of surface such as wood flooring so they don't resonate the floor/building.
     
  3. walterw

    walterw Supportive Fender Gold Supporting Member

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    I would guess out in the center would give you a little more even coverage, even without the reinforcement from the wall. Plus, your bass on that other side should provide a bit of lows to fill that zone.

    As for the main that's right there, why not stack the two subs and put that main on top of them to get a smaller overall footprint?
     
  4. sdenney78

    sdenney78

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  6. two fingers

    two fingers Loud Mouth Know It All Blowhard

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    Yep put them out front if you can. Use them as an extension of the stage almost. Tell the front man to hop up on the and let it rip. Against one wall as a pair seems like it won't work. If the places hold that many people they can spare a couple of square feet for subs right down front.
     
  7. walterw

    walterw Supportive Fender Gold Supporting Member

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    i think actually centered in front of the stage was out;

    i was suggesting over on guitar player's side, so stage left but centered in the room, and maybe even stacked and used to put the top box on.
     
  8. hopturn

    hopturn

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    Yeah, guitar player side is on the right (if looking at stage) but that front corner is basically right in the center if the room with a brick wall about 20 feet behind it. Won't I lose a dB boost by not coupling them to a wall?
     
  9. walterw

    walterw Supportive Fender Gold Supporting Member

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    Maybe; try it and compare if you have the time. Sometimes better coverage or even line-of-sight issues have to trump perfect efficiency.
     
  10. sdenney78

    sdenney78

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    Based on my previously mentioned website, I think coupled in the location that's closest to being centered in the room may be your best option.
     
  11. hopturn

    hopturn

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    Thanks everyone. I'm just now, at 37, trying to be more sound-educated. I'm going to try centering/coupling the subs this weekend.

    One last question: Friday's stage is about one foot off the floor and has a metal waist-high barricade that goes around it. It's a wild party bar full of drink-slinging crazies...a great venue, to be sure. Could I leave the subs onstage, or do they have to be on the dance floor? I just know the subs would get drinks poured in them. The same general room description would spply as stage left wiuld be the center of the room. Would they lose a lot of noticeable bass response a foot up like that?
     
  12. sdenney78

    sdenney78

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    "Placing bass speakers together - so that their output is acoustically coupled - will yield an increase in level. This can be as much as 3dB (the equivalent of a doubling in power) when compared with output from the same speakers placed further apart.

    Similar increases in level can be achieved by placing bass speakers against solid boundaries (floor and walls): bass speakers should almost always be placed on the floor. As this is their usual position, placing them elsewhere - on stage, for example - will usually result in a perceived reduction in level.

    Placing speakers against walls - whilst yielding further increases in level - may compromise other aspects of the sound. The mid/HF units always need to be forward of the performers, so placing bass speakers against the back wall adversely affects time alignment. Depending on the size and layout of the venue, placing the speakers against side walls mayalso compromise time alignment. Placing them against walls also has effects on room resonance (www.astalsound.com/bass_pattern.htm)."
     
  13. walterw

    walterw Supportive Fender Gold Supporting Member

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    you wouldn't need the room onstage for the band?

    again, you might get the slightest nominal loss of efficiency, but if it's worth it to keep them safe, then do it.

    what about the top box on that side? would it still go on a stand on the floor, or could you just set it on the stack of subs?
     
  14. TimmyP

    TimmyP

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    2' cancels 140Hz, 4' cancels 70Hz, 8' cancels 35Hz. Optimally, the subs should be within 2' or more than 8'.
     
  15. hopturn

    hopturn

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    Yeah, the mains will still go on stands.

    Thanks, Timmy P...easy to remember that.

    One last thing...since I'm assuming we're all bass players here. If you run your bass signal into the mixer from your amp, then out from the mixer left/right to each sub, then from the sub to each main...should you band pass the mains so that they are only getting 100hz and above?
     
  16. Argento1980

    Argento1980

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    Hi, everyone. I wanted to ask if having rubber feet stoppers or whatever they're called at the corners of each cab has the same effect as raising the amp off the floor to avoid the coupling effect with the floor?
    And while I'm at it... excuse my ignorance but if the cabs are closed-back does one still need to avoid placing them in corners or against walls to prevent, again, the coupling effect?
    Thank you!
     
  17. walterw

    walterw Supportive Fender Gold Supporting Member

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    Non-sequitur question; yes you should be crossing over your tops for 100Hz and above (and the subs 100 and below), whichever way you run the bass into the PA.
     
  18. hopturn

    hopturn

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    I guess that was a dumb question...duh. Thanks everyone. Syncing buying this QSC powered PA (2 mains and two subs) we've really started sounding better...but getting he right sound has been a headache. I've been using my wireless to direct the sax player while he tweaks the mixer. We're thinking about buying that new Mackie wireless 16 channel mixer...anyone have any experience with those?
     
  19. Keithwah

    Keithwah Supporting Member

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    I would look more seriously at a used Presonus 16.4.2. It will also add the benefit of Capturing your show to hard drive in multi tracks for editing or evaluating. It's very easy to use and you've got a real piece of hardware to work with if your router takes a crap.

    Mackie still needs to convince me they aren't just boning consumers with another poorly manufactured product before I swing back to using them. I've had more failures with Mackie consoles than with any other brand. And i have sold several thousand of them in the padt 20 years plus since they were originally Tapco. Also the Behringer X32 digital console is very intense for the money! It truly is a Midas made in China. Very good buy for those not wanting to multi track. I have seen the Mackie and its Ok, but frankly, Presonus was the original mover and shaker in wireless iPad remote use and are still by far the leaders in remote iPad innovation. I sell tons of these and they work great! I've even got one of my own. I have also sold rap loads of Soundcraft SiC consoles, very nice for theatrical use as well as a live board. Decent iPad remote, but nowhere near as nice or as fast as Presonus.
     
  20. walterw

    walterw Supportive Fender Gold Supporting Member

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    around here at least the presonus has indeed kinda become the "digital mixwizard", the board that every local band and most of the local soundguys now use.
     

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