feedback's actual pitch?

[yamaha]

Parametric EQ's have some advantages, as they usualy have frequency, Q (with), and boost/cut. But they are often limited to 3 or 5 bands. Graphic 31 band EQ's have been used on monitors forever, and they work well, but your ears has to be at least a little bit trained. It's easy to make a mistake and cut a feedback harmonic, and not the actual feedback frequency. Cutting the harmonic will often stop the feedback, but you might need to cut 6dB of the harmonic, as to 2dB of the actual pitch would have been sufficient. Feedback supressors (automatic) are great tools too, especially for monitors.

The best way to minimise feedback is decent equipement, and proper gain structure. By decent, I don"t mean super high priced mics. SM57's and 58's are great. Gain structure becomes more of an issue. Ideally, make sure your mics clip just a bit at max output. Use some compression, if you have any. Not as an effect, but to limit your gain should the input become louder during the performance. Use low cut filters on everything except bass drum and bass.

And for some reason, kits pushed to close to their limits feedback more than kits that are more powerful at the same level. My band has 2 PA systems. A small 800 watt, and a bigger 5000 watt. We almost never hear any feedback from the big kit, but the small one, we have to position speakers, play a lot with EQ, etc....

 

[fokof]

+1 parametric , and Full if possible , Bandwidth is your friend.

graphic EQ are also named 1/3 octave , why ?
You guessed it , each frequency is a major third from the one below
C-E-G#-C-E-G#-C-E-G#.....

 

[Twnty1inRF]

I use a DriveRack PA to ring the mains in the room quickly before we play. I don't use the pink noise generator unless we can do an early load in before customers show up, we play mostly bars and the general rule is if people are eating you can't use the RTA.

I also use a feedback destroyer on the wedge monitors to grab any frequencies kicked up when the singer moves around (the drummer and I use in ears).

If you want to see what frequencies are feeding back, here is a cool tool that a friend uses that makes the LEDS glow more brightly on the offending freqs http://www.sweetwater.com/store/detail/HQ231/

 

[MNAirHead]

RTA is a help.. or Roland Anti Feedback if you're just learning.

 

[ihateusernames]

there are plenty of graphic eq's on the market with feedback detection built in, the 'hot' signal will light the slider for you to quickly pull down that frequency - or adjust your parametric.

a google search for "feedback trainer" will get you to a free download to - well - train your ear to feedback.

 

[JTE]

Well, you don't have to try each EQ fader, do you? With the EQ flat, you turn up the gain on one system until you just start hearing some feedback. Like learning to play, it takes some experience, but you can narrow it down to low, mid, highs. Then you try a fader in that area. The more you do it, the faster your ear discriminates which fader to go to.

In that sense, knowing approximately what note is at what frequency can be a big help- that is, if you know what range 440 Hz is, then if you hear some ringing in that area it'll help lead you to a fader in that range. But knowing that it's A instead of Ab or Bb probably is less important.

John

 

[Emanuel Apascaritei]

Parametric EQ's have some advantages, as they usualy have frequency, Q (with), and boost/cut. But they are often limited to 3 or 5 bands. Graphic 31 band EQ's have been used on monitors forever, and they work well, but your ears has to be at least a little bit trained. It's easy to make a mistake and cut a feedback harmonic, and not the actual feedback frequency. Cutting the harmonic will often stop the feedback, but you might need to cut 6dB of the harmonic, as to 2dB of the actual pitch would have been sufficient. Feedback supressors (automatic) are great tools too, especially for monitors.



....

I don´t think the harmonic is louder than the root freq of a feedback IMHO, or maybe I understood you wrong