Equalizer Tech Notes
There’s no amount of equalization that can help a poorly designed sound system (or room) that has reverberation and delay issues, excessive background noise, distortion evident in your system, poor quality music tracks (stems), vocalist singing out of tune, musicians that have tuning or tone issues or playing wrong notes or in the wrong key, or if someone is giving a speech at a podium and standing way too far from the microphone.
Keep in mind that during “Live Performances” your ears will “De-Sensitize” as the night goes on.
You cannot fix poor low frequency issues due to the speakers being “out of phase” with equalization – this can damage the speakers. Equalization cannot correct polarity / phase issues.
Here are some proper / proven ways to approach equalization
- Use Subtractive EQ – If there’s too many highs, don’t turn up the bass, turn down the highs. What is Subtractive EQ? – Video Clip!
- All adjustments should be small, once an adjustment is made, sit back and listen to the adjustment before making the next adjustment, and so on. Listening is a very important aspect of proper Equalization.
- There is a cutoff point with equalization – there is only so much equalization that a sound system can take before the system’s sound quality starts suffering and sounds worse than when you started.
- Feedback – There are a few ways to deal with feedback with the first approach being to turn down the fader on the channel that seems to be the culprit (use this approach as a quick, temporary fix). Once you stop the feedback from annoying everyone in the audience – you can now start to troubleshoot further.
- Is the microphone too close or in front of the speakers? Move the microphone!
- Is the singer too far away from the microphone? Tell the singer to get closer to the microphone!
- Is the talker or singer projecting at an unusually low level? Ask them to talk or sing louder or you should look for a microphone that is more sensitive than the one you are using.
- Is the monitor speaker in the proper orientation for the type of microphone being used? Move the monitor as close into the microphone’s “rejection” area as possible (refer to the microphone’s documentation). Note: Sticking a monitor on stage where-ever you want to is not how it’s done (See bottom of Page 52).
- Is there an open microphone that should be muted? Mute the open microphone!
Remember – small changes are always the best approach with Channel EQs, and you also need to keep in mind that there is a point at which the sound systems quality will start degrading if you are not careful.
The “Smiley Face” and “Sad Face” EQ Strategy: In the image above, you will notice that Channel 1 (top half) sort of has a “Smiley Face” pattern going on. Channel 2 (lower half) has a “Sad Face” pattern. I cannot count how often these “canned” patterns were used by the so-called Audio Professionals I have dealt with over the years. I would spend hours working on the main EQ for the house system with an RTA (Real Time Analyzer) and pink noise. When finished – I’ve had several “Audio Pros” walk in afterward and change the EQ settings to either a Smiley or Sad face and think it’s better! I’ve included this example to make a point – there’s a right way to EQ and a wrong way to EQ a system. Walking in and changing 4-5 hours’ worth of EQ work without listening to the system is not the way to approach system EQ. Everyone will hear the system differently, and we should understand that Equalization can be a very “subjective” process! My point is that no “one setting” works for all audio systems when it comes to Equalization. You want the “Main” system EQ to be as “Flat” as possible (then leave it alone), then only adjust the EQs on the individual Mixer channels as needed.
Tech Tip: The best way to develop expertise and knowledge regarding audio systems is to listen! Use your Ears! Levels need to change as audiences become larger and smaller. Don’t ever settle with “canned” adjustments (which means marking the Mixing Board and setting the fader to the same mark every time). Adjust with your Ears to what’s going in the audience right now! In Real Time!
I spent a reasonable amount of time on this Equalizer section, and there is enough basic information here for a beginner Audio Technician to get started (and survive). I wanted to ensure that the reader understands that an Equalizer is a significant piece of the puzzle regarding the overall sound quality of a final mix. Whether it’s Live Sound, installed systems, outdoor systems, theater systems, a two-piece band, or just one instrument – Equalizers can “make or break” the overall quality presentation for the listening audience.
