In the first installment (here) of this two-part series, I covered many of the basics of how to listen for specific problems in our work of sound reinforcement. The better we can discern between different kinds of problematic sounds, the more quickly we can visualize the correct solution/s, saving precious time and making us more valuable to our customers. Who doesn’t want to save time and money?

This time out I want to cover some of the concepts dear to me as both a musician and a sound technician.

Electronic Or Mechanical?

One of the most vexing problems when setting up for a live performance is that, well, musical instruments are very sensitive to sound! It makes sense, of course – to be able to produce sound, instruments must have flexible, resonant elements of some kind. Not to worry so much with brass or woodwind instruments. But percussion/drums, pianos, and stringed instruments are ripe for resonance from induced sources (i.e., the PA system or loud guitar amp).

It’s really a good idea to know what a resonating snare drum sounds like because there are times when it is easy to mistake it for something else. “Every time the singer (or guitarist, or bass player, etc.) hits this one note, I hear a buzz.”

If we were to chase our tail looking for something in the PA system, we might waste time we don’t have, when the answer is simply to unhook the snare on the offending drum (assuming it isn’t being used at the moment), or re-tuning the snare to a slightly different pitch. Just like on a date, though, have a conversation first, and maybe buy ‘em dinner – definitely don’t rush up there and
start touching and tweaking the drums – drummers don’t take well to that!

Another issue with mechanical noise can be a loudspeaker cabinet that’s cracked, has an open seam, or maybe has a loose driver. This can be one of the mains or monitor wedges, or it might be a guitar or bass cabinet. Again, it will be most noticeable on single notes, usually one of the resonant frequencies of the cabinet.

Close miked stringed instruments like violins, violas, cellos and upright basses are fairly notorious for ringing on certain notes. It might sound like feedback in the PA, and in a way it is, but the instrument itself is acting as a local “acoustic amplifier” (because that’s what they’re designed to do). Again, it is important to know the difference in the sound.

Often, again, there will be one note that really sticks out, and every time the player hits that note, it sounds loud and rings far too long. A light touch on the channel EQ at that frequency, with a fairly narrow Q, might help bring that down. Or, the instrument might be positioned on stage right in an acoustic mode and a small re-positioning might solve it – just a few inches away or a foot or two.

Formants: The “Voice”

Since we’re speaking about instruments, one of the really important concepts to understand is about formants. Definition: “A resonance frequency or frequencies of the vocal tract (or acoustic instrument); frequencies that are most successful in traveling through the vocal or instrument; depending on the shape, different frequencies are transmitted better or worse.”

In other words, it’s like a fingerprint for that acoustic sound source. It’s also one of the reasons we can identify people by the sound of their voice, even on a limited reproduction device such as an old telephone. It’s why, when recordings are sped up or slowed down, we can easily tell – think of Alvin and the Chipmunks.

Today, we have DSP technology that allows us to alter the speed of playback without moving the formants so sounds can still seem relatively natural. Think of the disclaimers at the end of a radio commercial – they speed up the recording but it still sounds like a voiceover person and not a chipmunk.

Why am I spending so much time on this subject? Because as sound professionals, we have the power to mess this up. We can futz with EQ knobs on the console and make a tenor sax sound more like a trombone. Or we can make a viola sound more like a tenor sax. Perhaps there are times this might be desired, but I will venture a guess that these times are in the minority, especially when it comes to singers.

Conversely, we also have the power to make people sound even more like themselves by highlighting the parts of the voice that give them their unique sonic signature.

In terms of problem solving, if you’re working on a mix and wondering why the singer doesn’t sound “right,” think about formants. Is the sound “bloated” or “thin” or “dull,” or simply “doesn’t sound like them” – this may be the reason. Maybe it’s the microphone, or the EQ, or a funny frequency range in the house PA.

Chord Inversions

Another and even more subtle but still important concept is that musical chords have “voicings” or “inversions” that give the band or the arrangement a particular harmonic character. The best arrangers and composers know all about this and use it all the time. In simple terms, a C major chord (triad) consists of a C (lowest note), E (middle note) and G (highest note).

The “first inversion” is where the low note is the E, with the G in the middle and a C on top. The “second inversion” is with the G on the low note, the C in the middle, and the E on top. Each version sounds different even though the same three notes are all there in the chords.

Again, as sound reinforcement technicians, we can mess this up. Imagine a horn section or a vocal ensemble, anything with multiple instruments playing chords, but somehow, we have the balance wrong (the middle voice instrument is too loud, for instance, or one of the mics is missing or off-axis). We can influence how the audience hears these chords – as if they were wrong inversions.

It may be that no one in the audience notices these problems if they can still hear the lyrics, but our job is to get it right. Sometimes even subtle issues like this can make or break a performance.

You Can Tune A Piano, But…

One thing that we often have little control over is whether players or instruments are in tune. Pianos are notorious for this problem, and good piano tuners make good money. Live audiences are fairly forgiving but if the artist/s hear an out-of-tune piano on a live recording, they won’t be happy.

Again, we may not have control over this, but if we’re on a regular gig, we can increase our value by at least notifying a production manager or other “in charge” person that the piano is out of tune. If they can’t get it tuned before the show, how about using a keyboard instead?

Finally, one instance of tuning that we might be able to influence is driven by the musicians’ ability to hear themselves and others. This largely comes back to whomever is mixing monitors. By listening to what is happening on the stage, we can sometimes identify the root cause.

Rather than simply laughing at the violinist who “can’t play in tune,” maybe ask that person if they can hear OK, and perhaps one step further, ask them which instrument on the stage is their pitch reference. Maybe it’s the piano, or the bass, and we don’t have enough of those in their cue mix.

With these two articles, hopefully I’ve provided plenty of thought-provoking concepts on how we can hone our craft by improving our listening skills. While there are some things we inevitably can’t control, there are quite a few things we can at least influence – if not outright fix – if we know what we are listening for.

Stay safe out there, and I look forward to meeting you in the trenches sometime soon!