How to EQ a Room
- Place a dynamic microphone with a cardioid pattern at the center of the stage and point it toward where a person would speak or perform.
- Ask anyone making noise on the stage to leave so they don’t corrupt the EQ process.
- Set all of the microphone’s EQ channels on the mixing board to flat.
- Bypass the compressor-limiters, feedback destroyers and other similar processors so you get a clean signal.
- Move the microphone and instrument channels in the monitor(s) to about where they need to be for the performance.
- Adjust the Main House EQ so it’s set to the Center position.
- Turn the mixer’s Input Gain to “Off” and the channel fader to 0dB or -10dB. The fader setting on the Main Out needs to be at -10 or 0dB.
- Raise the Input Gain slowly until you hear a ringing noise from the speaker system. Turn it down until the sound stops.
- Manipulate the channel fader to cause the speaker system to ring at a low, nearly steady tone.
- A real-time analyzer will show you which frequency is ringing, but
it isn’t the most accurate reading. If you have a multimeter with
frequency, plug it into the Headset Out and use the Pre-Fade Listen
(PFL) Output as a signal. The better reading you get, the more accurate
your adjustments when you want to properly EQ a room.
- Decrease the ringing by -3dB on its frequency, which should eliminate the ringing sound.
- Raise the fader once the ringing stops.
- Repeat these steps for each slider until several of the frequencies rise at once or until one of the frequencies hits -12dB.
- If you hit the EQ’s bottom before this happens, there’s a problem with the room itself or with the system design.
- Turn the master monitor volume back to your preferred level for the performance.
- Ask someone to stand at the microphone(s) and instrument(s) and check them so you can adjust the levels of each individual input.
Source (Wikihow)
