Now let’s zoom out a bit and talk about exposure to energy differentials from the norm or average. Exposure of our humanly bodies to too much sunshine causes sunburn.
If we’re exposed to prolonged periods of below freezing temperatures, it leads to all kinds of not good things if we’re under-protected. So does exposing our eyes to the spark of a MIG welder so bright that it can be blinding and standing near a jet engine so loud that it can be deafening.
Exposure to energy in moderate amounts can be desirable, but too much exposure is often problematic.
Understand that I’m not saying how much is too much, but rather, I’m offering some observations about parallels between exposures to different types of energy. We can jump into very frigid water for short periods of time as demonstrated by the annual “polar bear plunges” around the world. We can wave our hands briefly through fire with no ill effect, glance at the sun, or comfortably lay upon a bed of nails if there are enough nails to evenly distribute the small points over a large portion of our body. Short-term exposure to larger peaks or longer term exposure to an even average is typically non-detrimental and perhaps desirable.
Sweeping back into the sound world, we expose our listeners to volume levels and tonal balances of audio energy. If the frequencies presented are in a narrower frequency range for a short period of time, like a snare drum or single bright note of a loud electric guitar, it’s all good as long as it’s not overly repeated or is offset by balancing energy shortly thereafter. Just as our bodies seek a balanced temperature for long-term exposure, our ears seek a balanced frequency response as well.
Thus while mixing, I set up the RTA to measure the room sound with long averaging times and actively switch between 10-second averages, as well as averages over several minutes and averages over several songs. The goal is to be able to measure the “tonal balance exposure” over time that the audience is immersed in. I want to assure that tonal balance over longer time frames does not drift too far from the initial comparative reference point established with the headphones.
To gain clear and predictable control over the tonal balance of a sound system, I set up three distinct stages of EQ. First are the console channel EQs, which are responsible purely for equalizing the microphone-instrument (or vocal) to sound “correct.”
“Correct” can be whatever we wish it to be, but it’s the job of the channel EQ, combined with mic choice and positioning, to get us there. When we cue that input channel up in headphones, it should sound the way we desire it to sound.
Second, it’s the job of the system processor to EQ the loudspeakers to sound correct in the enclosure they’re mounted in, and also to compensate for the EQ differentials caused by using multiple loudspeaker enclosures in an array. In a perfect world and in an ideal anechoic chamber, a signal sent to the loudspeakers sounds exactly like the source. The system processor has nothing to do with correcting for the sound of the venue.
Finally, the house EQ is tasked with compensating for the loudspeaker array-to-venue combination. During a show, knowing where to make adjustments is crucial. If the room gets duller when the audience arrives, where do we EQ? The house EQ, because it was a room change. If the drummer’s snare gets duller over the course of the show, we change console EQ on the snare channel.
Further, if someone climbs up and adds more loudspeakers to the array and re-angles everything, first we wonder why the heck they would do that, and next we would adjust the system processor to compensate. If the room heats up or cools down – house EQ. If the venue humidity changes – house EQ. If the guitar player switches to a brighter guitar – channel EQ.
What I find interesting is that most of the EQ changes over the course of a show typically occur with the biggest uncontrolled variable, the room. The tonality of the loudspeaker arrays rarely changes so there is almost no reason to alter the system processor settings, even from venue to venue when setting up similar arrays! The tonal balance from the stage may jump around a bit from song to song and over the course of the show, but these changes are either intentional or can often be managed by well thought-out usage of compressors, mic placement and mic chart decisions.
It’s the room or venue sound that is the real wild card, remaining in a state of flux with constantly changing temperatures, humidity, more people, less people, wind, refraction from changing thermal layers, and so on. If a mix is set up well and the band is halfway decent, then the art of mixing is not about hunching over the console but rather stepping back and keeping the house EQ dialed in, and presenting the optimum tonal balance exposure you desire the audience to experience.