EQ Or Off-Axis?

A case-study in fixing a monitor mix.

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The opinions expressed are mine only. These opinions do not necessarily reflect anybody else’s opinions. I do not own, operate, manage, or represent any band, venue, or company that I talk about, unless explicitly noted.

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I’m really interested in monitors. They contribute immensely to the success (or crushing failure) of a show, affect musicians in ways that are often inaudible to me, and tend to require a fair bit of management. I wrote a whole article on the topic of unsuckifying them. Some of the most interesting problems to solve involve monitor mixes, because those problems are a confluence of multiple factors that combine to smash your face in.

You know, like Devastator, the Decepticon super-robot formed by the Constructicons. The GREEN (and purple) super-robot. From the 1980s. It was kind of a pain to put him together, if I remember correctly.

Sorry, what were we talking about again?


So, my regular gig picked up a “rescue” show, because another venue shut down unexpectedly. A group called The StrangeHers was on deck, with Amanda in to play some fiddle. (Amanda is a fiddle player in high demand. If she’s not playing with a band, she is being recruited by that band. I expect that her thrash-metal debut will come shortly.) We were rushing around, trying to get monitor world sorted out. When we got to Amanda, she jumped in with a short, but highly astute question:

“The vocals are loud, but I can’t really make them out. They sound all muddy. Is there a problem with the EQ, or is it something else?”


Amanda’s monitor was equalized correctly. The lead vocal was equalized correctly. Well…that is…ELECTRONICALLY. The signal processing software acting as EQ was doing exactly what it should have been doing. Amanda’s problem had to do with effective EQ: The total, acoustical solution for her was incorrect.

In other words, yes, we had an EQ problem, but it wasn’t a problem that would be appropriately fixed with an equalizer.

One of the lessons that live-sound tries to teach – over and over again, with swift and brutal force – is that actually resolving an issue requires addressing whatever is truly precipitating that issue. You can “patch” things by addressing the symptoms, but you won’t have a fix until you get to the true, root cause.

What was precipitating the inappropriate, total EQ for Amanda could be boiled down to one fundamental factor: She wasn’t getting enough “direct” sound.

To start with, she was “off-axis” from all the other monitors she was hearing. Modern loudspeakers for live-sound applications do tend to have nice, tight, pattern control at higher frequencies. As the frequency of the reproduced content decreases, though, the output has more and more of a tendency to just “go everywhere.” Real directivity at low frequencies requires big “boxes,” as the wavelengths involved are quite large. Big boxes, however, are generally not what we want on deck, so we have to deal with what we’ve got. What we’ve got, then, is a reality where standing to the side of a monitor gets you very little in the way of frequency content that contributes to vocal intelligibility (roughly 1 kHz and above), and quite a lot of sound that contributes to vocal “mud.”

Another major factor was that the rest of what Amanda was hearing had been bounced off a boundary at least once. Any “intelligibility zone” material that made it to Amanda’s ears was significantly late when compared to everything else, and probably smeared badly from containing multiple reflections of itself. Compounding that was the issue of a room that contained both people and acoustical treatment. Most anything that was reflected back to the deck was probably missing a lot of high-frequency information. It had been heavily absorbed on the way out and the way back.

Figuring It Out

This is not to say that all of the above snapped instantly into my head when Amanda asked what was wrong. I had to have other clues in order to chase down a fix. Those clues were:

1) Before the show, I had put the mics through the monitors, walked up on deck, and listened to what it all sounded like. For the test, I had a very healthy send level from each vocal mic to the monitors that were directly behind that microphone. Vocal intelligibility was certainly happening at that time, and although things would definitely change as the room changed, the total acoustical solution wouldn’t become unrecognizably different.

2) Nobody else had complained. Although this is hardly the most reliable factor, it does figure in. If the vocals were a muddy mess everywhere, I’m betting that I would have gotten more agreement from the other band members. This suggested that the problem was local to Amanda, and by extension, that a global change (EQ on the vocal channel) would potentially create an incorrect solution for the other folks.

3) On the vocal channel, the send level to the other monitors was high in comparison to the send level to Amanda’s monitor. This was probably my biggest and most immediate clue. When other monitors are getting sends that are +9 dB in relation to another box, the performer is probably hearing mostly the garbled wash from everything OTHER than their own monitor. If the send level to Amanda’s wedge had been high, I might have concluded that the overall EQ for that particular wedge was wrong – although my encouraging, pre-show experience would have suggested that the horn had died at some point. (Ya cain’t fix THAT with an equalizer, pilgrim…)

So, with the clues that I had, I decided to try increasing the send level to Amanda’s monitor to match the send levels to the other monitors. Just like that, Amanda had a LOT more direct sound, everything was copacetic, and off we went.