Feedback From The Bass...

Discussion in 'Live Sound [BG]' started by Gearhead17, Jan 6, 2013.


  1. Gearhead17

    Gearhead17 Supporting Member

    Joined:
    May 4, 2006
    Location:
    Arlington Heights, IL
    I need some help and advice about what do when a feedback loop occurs. Also, I am not sure if I am stating this correctly, but here it goes!:)

    I am constantly getting blamed by my singer and guitarist when a feedback loop happens on stage and it sounds like a droning/humming single bass note. They usually look at me and give me that look "it's you dude!". When it happens, I immediately turn the volume to zero on the bass. There is no sound out of my rig and the feedback keeps going. Sometimes it magically disappears; probably because the sound guy took care of it. Other times, the feedback is so bad that I have no clue what to do and those guys get frustrated with me. Then the singer will usually ask for me to adjust "something" to get rid of it, I pretend to adjust something and it goes away???

    Hopefully I figured this out - the drummer has me in his monitor cabinet at certain shows. I believe the sound of my bass through HIS monitor is traveling back into the drum mics. And since he has certain parts of his kit in his monitor cabinet, my bass tone keeps coming back in. So in reality, it's the sound guy's issue when that type of feedback occurs - correct? The mics should be placed differently and/or certain frequencies need to be notched out of the drum monitor - right?

    Lastly, I try to keep my rig away from the drums as often as I can - so I know that is not the issue. Any help is appreciated.
  2. TimmyP

    TimmyP

    Joined:
    Nov 4, 2003
    Location:
    Indianapolis, IN
    It's either stage resonance feeding up the stands into the vocal mics, or it's one of the drum mics.
  3. derrico1

    derrico1 Supporting Member

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    Apr 12, 2005
    Location:
    Charlottesville, VA
    If the drummer's monitor is hot, it can cause his drums (usually the floor tom) into sympathetic resonance. That will sound like a low frequency feedback. Stages with a lot of spill from FOH can also create this problem. Bringing down the stage levels by the drum kit will help, and even taping or retuning the bottom head of the offending drum(s) will sometimes do the trick.

    FWIW, I'd also discourage the habit of pretending to fiddle with your bass amp to fix a problem that you're not causing.
  4. modulusman

    modulusman

    Joined:
    Jan 18, 2004
    Location:
    montana
    Next time it happens look back at the drummer and say "its you dude". Most likely cause is a drum mic.
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  6. tbirdsp

    tbirdsp Supporting Member

    Joined:
    Sep 18, 2012
    Location:
    Omaha, NE
    IF you turn your bass volume to zero and it doesn't instantly go away, it's not you. Agree with the others on likely causes - I've found that that "tone" of feedback is usually around 125 hertz.
  7. jad

    jad

    Joined:
    Aug 29, 2002
    Location:
    Pittsburgh, PA
    Yeah, when it happens to my band, it usually the floor tom. Try gating the drums if you're not doing it already, and bring down the drum monitor a bit.
  8. Gearhead17

    Gearhead17 Supporting Member

    Joined:
    May 4, 2006
    Location:
    Arlington Heights, IL
    OK. I had a feeling it was not caused by my gear.

    I do not run sound at shows - almost always have a provided sound crew. At certain shows, I found out the sound guy was not gating the drums. I am assuming it's the same issue at other shows. Sometimes the feedback is just insanely loud, I find it weird that the sound guys at some of these shows do nothing about it or assume it is coming from somewhere else.

    It's funny though, when my singer comes up to me pleading with me to fix the "feedback", and I pretend to adjust something......then it goes away and he is darn HAPPY that I fixed it. :eyebrow: Yeah, no more fake adjusting for me.

    The other place feedback is a concern features two quad 15 cabs BLASTING a ridiculous amount of low end. They are right in front of the stage and I can HEAR AND FEEL my bass tone all night. I reduce my stage rig heavily below 150hz and also reduce the 300hz area just so my bass tone does not take over....
  9. Floyd Eye

    Floyd Eye Banned

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    Feb 21, 2010
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    St. Louis
    I agree. It's a drum mic.
  10. mellowinman

    mellowinman Guaranteed to break the Ice at Naughty Parties Supporting Member

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    I agree with everyone who says drum mic, and it's monitor feedback. The OTHER possibility is that it's the mic on the guitar amp. There's a lot of ways to control it, but one thing is, to limit that bottom end on the guitar amp mic. The guitar only goes so low, and I doubt it goes as low as that feedback you're hearing.

    Least likely cause:

    Your bass rig.
  11. pflash4001

    pflash4001

    Joined:
    Dec 2, 2011
    Like mentioned earlier, if your rig is down, it isn't you. It is more than likely a drum mic in the monitors. Next time that happens I'd just look back at those guys with a cheesy grin and let that offending frequency riiiiiing....smiling at 'em the whole time. The drummer needs to work on mic placement, spkr placement, gating, gain, and eq. Or get the sound guy to tack that freq down...
  12. Joe Nerve

    Joe Nerve Supporting Member

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    Didn't read all the responses, but I think the first and most important thing to establish is where the feedback is coming from. What you say about it sometimes disappearing and sometimes not when you fiddle with your bass is a little confusing. :)

    Next time it happens, I'd shut my amp, and let everybody know. If it stops, then I'd say it's safe to guess it's somehow coming from you. Why, would be the next step, and I saw some good suggestions here in what I did read. The mics in front can often be responsible for this kind of thing, especially if they're in direct line with the amps. People often think too if the feedback is in a low frequency that it MUST be the bass, but guitars can put out some real nasty low end stuff.
  13. Gearhead17

    Gearhead17 Supporting Member

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    Arlington Heights, IL
    Yeah, some of those sound guys refuse to gate the drums. I have run into that. No one in the band runs sound, it's 95% provided at our shows. I am at their mercy every time....

    I will say this though. The last two shows we just did turned out great and we did not have one feedback issue. NYE we had a feedback issue, but the sound guy there took care of it in about 30 seconds or less.

    I have also seen the guitars cause feedback issues - mainly because the sound guy let too much guitar low end rumble through the subs. At that particular show, the drummer had a monitor with a subwoofer. Guitars through a woofer next to the drum mics just creates a recipe for disaster.
  14. fokof

    fokof One day ,I'll be in the future Gold Supporting Member

    Joined:
    Mar 16, 2007
    If your rig is miked and you turn your bass to zero, it still can be you , even if you turn your low end down.
    Problem with a Miked bass cab (And no DI) is that the sound man have to leave low end content for the FOH , excellent recipe for what you are describing.

    Are you miked or DI'ed ?


    Is there a sound engineer ?


    If he's not sitting at the bar , cruzing the waitress , maybe he can mute/un-mute each input at the board , one at a time , until the hum disappear. When he mutes an input and there is no more humm , that's where the problem is. Sometimes these can also be caused by multiple mikes.
    Very easy to do while the band is playing.
    Better to do this and spot a problem in 30 seconds than letting that ring go for the whole night.
    If the soundman is the toilet doin' crack and your on your own , if a feedback happens , one thing you could try is to unplug the problematic monitor to try to isolate where the problem is.If it's a FOH thing , that won't help you .
    You could also unplug a live dynamic mikes if the Phantom is not on at the board.

    Usually ,(as a rule of thumb but this is not true all the time ) a low end feedback mean that the source and the speaker are farther apart , the closer they are together the higher the pitch.
    And no , there is magical frequency , cut this & that I can say to you over the internet ....
    If the ring is low pitch , I'd blame the FOH.

    BTW , if there is supposed to be a soundman , why do the others guys in the band blame you ?
    I don't get it.....
  15. Gearhead17

    Gearhead17 Supporting Member

    Joined:
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    Location:
    Arlington Heights, IL
    Almost every show I am running through a DI (just my bass with an Xotic Blender with a VT Bass used on certain tunes). Any time the feedback has happened, I have not been miked.

    Sound guy's are provided for our bar gigs. Any situation I have talked about on here was always with a sound crew.

    I don't know why I get blamed. I always put my hands in the air and let everyone know it's not me. I make sure to turn my bass down 100% every time it happens just to make it is not me. My rig is silent on stage. Even with the distortion channel, I can't get any kind of feedback. It's not a crazy tone.
  16. uhdinator

    uhdinator

    Joined:
    Apr 20, 2010
    Location:
    Maine
    Some causes:
    Hollow stages resonating
    Too much LF in vocal mic's
    Drum head type and tuning/resonating
    Too much LF in Tom and snare mic's
    Missing rubber feet on mic stands
    Too much LF in drummers monitor bleeding into drum mic's/resonating the drums.
    Cheap drum mic's

    Things to try:
    Engage HPF on all mixer channels except kick, and bass. You don't need 100hz or below on voice, guitars, snare etc.

    Use moon gels, tape or something similar to dampen drums ringing or check tuning.

    Face your bass amp across stage so drummer can hear it better instead of feeding bass to his monitor.

    Adjust drummer monitor placement

    Use an Auralex gramma pad under your bass rig.

    Use less mic's or different mic's on drum kit.

    I was doing a sound check at a gig with no stage/hardwood floor. I was noticing an inconsistent rumble while checking signals and people were walking around setting up. I put on my headphones and started solo'ing channels, then went over near the offending source and stomped my feet while walking toward the source mic causing the resonance to increase as i got closer to confirm it.

    The guitarist had a small round base mic stand for the mic on his cabinet.
    I picked it up and looked at the bottom.....no rubber pads on the base.
    The steel sitting on the wood floor was transmitting vibration from people walking. I got a clean bar towel, soaked in water and rang it out, folded it into a small square the size of the mic base and put it under the stand. Problem solved.

    Must would not realize how a little thing like that can cause a problem.

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