NOTE: This node is written in regarding a professional sound system in a live environment (I.E. not for studio use), not a home sound system. It is highly desirable that the channel on the mixer will have an an EQ in which the bands have adjustable bandwidth and frequency. If not, that is fine but half of the info here will not apply. A low cut filter is also extremely handy.

I will write 3 different guides here, one for how to EQ in the shortest time possible, (good for a just a speaker at a lecturn or the like), how to EQ for a singer while time is short (when is it not in theater?), and how to EQ where time is no object and/or quality is paramount. First I will include an introduction to the controls on an EQ.

Basic EQ Controls An EQ generally will be divided into four bands, Low, Low-Mid, High-Mid, High, these names reflect the frequencies they alter. Each band will have a knob for cutting or boosting that frequency range. If the bands have frequency controls, you can control the frequency with extreme finesse. It is also common to have a control for the bandwidth of a given EQ knob. The last control is a low-cut filter, which cuts all frequencies below a certain frequency.

General Concepts:

  1. Your first job as the audio engineer is to make the person heard, this generally comes above sound quality
  2. Just because one EQ setting sounded good for someone else doesn't mean that it will sound good for whoever is now up on stage
  3. BE CONFIDENT, I notice that many first time technicians get nervous and are afraid to EQ, if you don't EQ it'll sound really bad, so trust your ears!
  4. An Audio Engineer's greatest asset is his experience, it's hard for novices with untrained ears, so these steps may take longer than it would take with a pro.


EQing as quickly as possible

Have the performer/speaker speak on the mic, preferably using their script or speech. If they are not available find an available stage hand to do this for you.Once they are talking start the EQing. Start by rolling up the low cut filter to filter out any pops if they are appearing (you'll notice these mostly on letters like P and Q). Then push the level up a little past what it will have to be during the actual performance, if you start to hear feedback curb those frequencies. After that, bring it back down to the normal level, adjust the controls till you have a decent tone but keep the levels such that they still cut feedback.

EQing when you have a moderate amount of time

Have the performer go onstage and make sure they are saying their lines at the same volume as they say them during the show (if they are singers make sure you make them sing). Now that you have them up there, listen to the sound for a second. If you hear some frequencies you don't like (which you undoubtedly will) roll up the level of the closest EQ band to the frequency that's bugging you. Widden the bandwidth on the EQ band. Then adjust the frequency till you find the one you want , reduce the bandwidth and isolate the frequency (at this point the offending frequency should be quite loud and their voice will sound quite bad). Then cut it. It should immediately sound better. Listen again, if you hear some frequencies that need to be boosted use the same method. After this, roll up the low cut filter to compensate for any poping you may hear. After this push the volume up past the point where it will be in concert, listen for feedback, compensate by cutting back frequencies that are feeding back (try to use as narrow a frequency range as possible)

How to EQ when you have plenty of time and quality is imperative

Have the singer or speaker sing (or speak if they don't sing) without a mic for a short period, take note of their vocal qualities. Try to match their original voice on the board with the EQ. After that is done, boost the volume to above the concert level and isolate and remove any feedback by isolating the offending frequencies and cutting them. After that listen to them sing, now is the time to enhance their voice. At this point experience and talent play the largest factor. You will have to use your own judgement to enhance their voice. Good luck! As a note on this method, I often don't try to match their original voices and sometimes just listen and say it needs this and do it. Replicating the original voice is primarily meant to help novices.

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