Feedback suppressor

Discussion in 'Live Sound [BG]' started by 73jbass, Aug 29, 2013.


  1. 73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    Got a DBX AFS224 for the pa rack I'm putting together,and I'm wondering if I need to put it before or after the crossover. Also since it is stereo,can I use one channel for the mains,and the other for the monitors?
     
  2. last thing in the before crossover, and after the EQ (if you have one) if not you should invest in one...
     
  3. 73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    EQ is next. Standard stereo 15 band I guess? How do you set the eq without a white noise generator something similar?
     
  4. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
    Hate to say this but you just have to use your ears. Headphones are worthless in most situations. I use a pink noise CD to set gain structure on my PA rig and the DriveRack's pink noise generator to ping the room...when possible. A standard stereo 15 band should be fine. Use one side on the PA main's insert, use the other between the monitor aux out and the monitor power amp. This will work if you're running the PA in mono (as you should!) and only require a single monitor bank. Note: the monitors, more than likely, will be the source of feedback, not FOH. The trouble source is more commonly the 400-600 hz and 4-6 khz regions. I routinely attenuate those sliders by 3-5 dB as a prophylactic measure...it works and not noticed by the vocalists.

    Otherwise...how ya been?

    Riis
     
  5. will33

    will33

    May 22, 2006
    austin,tx
    Yup, ears are the correct tool for the job. You can play some recorded music you're familiar with and adjust that to sound right out in the room. That'll get you close but you'll still need a little fine tuning for the live band, at least to clear up vocals, make sure lyrics are understood.

    And yes, a 15 band works fine for me, haven't needed a 31 yet.
     
  6. will33

    will33

    May 22, 2006
    austin,tx
    And yes, run in mono. There is no need for stereo in live gig sound, unless you have a keys/synth part that just has to have some pingpong type sound effect or you want to pan 2 or more guitars.

    Hint: Don't pan them very far or the sound is going to suck for everybody except the narrow strip of audience straight up the middle. Everybody else will just be hearing a whole lot of one guitar and very little of the other one.

    It's still better to run in mono and adjust the guitar tones to compliment each other, IMO.
     
  7. will33

    will33

    May 22, 2006
    austin,tx
    Another side benefit is it frees up a poweramp channel. Can run sub, main, frontline monitor mix and a separate drum monitor mix If needed with 2 poweramps.
     
  8. 73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    So would my signal chain be from the board,eq,suppressor,crossover?
     
  9. Zooberwerx

    Zooberwerx Gold Supporting Member

    Dec 21, 2002
    Virginia Beach, VA
  10. 73jbass

    73jbass Supporting Member

    Apr 17, 2004
    Ellenwood,Ga.
    I've been reading up on PA equalization,and I like some of the things I've seen. May not need the suppressor after all.
     
  11. uhdinator

    uhdinator

    Apr 20, 2010
    Maine
    With 1/10, 1/20, and 1/80th of an octave
    Filter resolution, the AFS 224 will affect your overall fidelity much less than trying to pull out a problem frequency with a 1/3 octave 31 band EQ. It will find and reduce the problem much quicker as well. The DBX drive racks incorporate this technology although its only 12 vs. 24 filters of the AFS 224.....
    It's very useful IMO and never drastically alters the overall sound quality while preventing feedback problems.
     
  12. Floyd Eye

    Floyd Eye Inactive

    Feb 21, 2010
    St. Louis
    Never used a feedback ferret or whatever you want to call them. 31 band on singer and drummer's monitors, none on mine( I don't bitch about monitors not being loud enough like they do) You don't need EQ to fight feedback on mains usually. EQ is for other stuff, but feedback usually isn't much of an issue FOH.
     
  13. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    Jun 12, 2021

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