1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

Boomy Stage Solutions?

Discussion in 'Live Sound [BG]' started by BluesWalker, Mar 29, 2009.


  1. BluesWalker

    BluesWalker Supporting Member

    Jun 17, 2008
    San Diego, CA
    I generally play through a 2x10 speaker cabinet (Mark Bass) and place is on an end so I have a two 10" speaker stack. I often play on boomy stages. In the Talk Bass collective wisdom which is the best was to solve this problem: a speaker stand to get the cabinet off of the floor, use a Gramma pad or similar homemade version, or something else?
     
  2. Steve

    Steve

    Aug 10, 2001
    Get the cab off the floor, get it out if the corner, get a sub or notch filter on the low end...

    All work to one degree or another depending on the cause of the issue.

    I'm sure there are other solutions as well
     
  3. ...also, if you have a parametric EQ try cutting the lowest frequencies (center around 50hz) a bit and try to use fresh roundwounds and even avoid humbucking pups....just some more ideas... .

    Jimbob
     
  4. jaywa

    jaywa

    May 5, 2008
    Iowa City, IA
    Two words: milk crate.

    It will keep the cabinet from coupling with the stage floor, and get the speakers up closer to your ears so you can run less volume.

    I have also heard it's better to back off the low-end EQ and run a little hotter volume than vice versa. I have tried this and can definitely say it's true.
     
  5. OtterOnBass

    OtterOnBass

    Oct 5, 2007
    Michigan
    So is the situation that you have horrible boom on stage, or that the low frequencies are overwhelming the whole room? If you can't hear yourself, then getting the amp up, or tilting it up at your ears will help. If the room is booming, then move the amp or turn down the overactive frequencies with an EQ. Low sound waves travel in every direction, like ripples in a pond, and the distances to walls and ceilings cause reinforcing or canceling of those ripples.

    In your case, I'd turn down the low EQ knob until the boom is just right. Be sure to have someone in the room tell you when it sounds good, often stages sound like crap when the room is great.

    Here's a link to a page on room modes. http://www.silcom.com/~aludwig/Room_acoustics.html
    In summary, the author states it's best to excite as many modes as possible for even response instead of having one or two frequencies dominating. I.E. Put your amp in the corner.
     
  6. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Two words: bush league. Get an amp stand.
     
  7. Hey don't go knockin the milk crate. Its a certified rock'n'roll standard!
     
  8. TimmyP

    TimmyP

    Nov 4, 2003
    Indianapolis, IN
    The amp stand will lower the overall bass response, and will also give you a notch in the response, but likely not at the right frequency. Leave it on the floor, and tilt it so it's pointed at your head.

    Get the bass right in the PA first. Then turn it off.

    Insert a parametric EQ, find the most offensive frequency, sweep the RQ till you find it (most easily done with boost), cut the band a bunch, then widen the bandwidth if necessary.

    Now bring the PA back up, and adjust the bass rig to remove the frequencies from it that are too hot in the house.
     
  9. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    You have to raise an amp a good two feet or so before you lose the benefits of floor coupling I forget the exact number). The only reason it sounds like you don't get the benefits is because you hear more increased mids and highs, not decreased lows.
     
  10. TimmyP

    TimmyP

    Nov 4, 2003
    Indianapolis, IN
    With the cabinet on the floor the reflections create a mirror image that boosts the bottom end. This goes away quickly in some cases, not in others. As to the notch, 2' will notch at 140Hz which is useful (as that's close to where many cabinets have a bump), but may not be the frequency you need to kill on a particular stage. See the frequency chart at http://www.padrick.net/LiveSound/CancellationMode.htm
     
  11. It sounds like you've got your answer here. There are three basic ways to address this issue.
    1. Tilt the cab
    2. Lift the cab
    3. Eq the problem frequency

    You probably won't get a consensus here about the best approach. It will depend on your unique situation and your perception of what you hear.

    I'll add that I've frequently had better luck cutting the offending frequency in the PA's eq. I don't typically run my bass through the PA, but the stage mics pick up my signal anyway and if it's a problem fq then it get's amplified in the PA just the same. Plus other instruments (like drums) are likely to produce the same frequency, so I try to find the problem fq and cut it both at my amp and in the mains and monitors.
     
  12. MNAirHead

    MNAirHead Supporting Member

    so Jimmy ----

    2 crates?
     
  13. Three words; black milk crate ;)

    Not at all disagreeing with you, Jimmy. It's about the functionality but also about the stage look. I'll use a pair of cable cases (black milk crates) to raise my 4x10. Failing that, a couple at the bar but use some black cloth to tarp them over.

    That'll decouple enough for 'floor bounce' but I still can get a lot of 'bloom' on some stages (VERY interesting gig last weekend; G resonated wildly). I'm trying to gear up some way of reducing conduction from cab to stage floor.
     
  14. jaywa

    jaywa

    May 5, 2008
    Iowa City, IA
    As long as you cover it up, doesn't make a difference what you use. I put my 4x10 on top of a $5 milk crate, "skirt" the cabinet with a black cloth that goes down to the floor and nobody is the wiser.

    I could buy an amp stand... but I would rather spend my money on things people see and that actually make a difference to my sound.
     
  15. testing1two

    testing1two Supporting Member

    Feb 25, 2009
    Southern California
    The fundamental issue is that you need to acoustically decouple the speaker cabinet from the stage. This is best accomplished by placing a dampening material between the cab and the floor. Best examples would be rubber feet, an amp stand with rubber feet, or something like an Auralex Gamma. I'm not a fan of milk crates as they tend to vibrate if they aren't sitting perfectly flat.

    EQ doesn't correct the problem for several reasons, the biggest of which is phase related. Yes, the stage acts as a giant resonator and enhances certain frequencies while canceling out others, but since sound travels at different speeds through different mediums, those frequencies arrive at the listener at different times compared to what's coming out of your speaker cabinet. Assuming that your speaker cabinet sounds better than the floor, it makes more sense to reduce the amount of stage vibration so the audience hears more of you and less of the floor.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.