How to Mix Sound, Session 4: Miking Principles and Practices (part 2)

Placing Mics

Lavs (lavaliere mics)

With a lav mike, you want the mike to be as close to the person’s throat as possible. The ideal spot is just below the collarbone. This allows the mike to ‘hear’ the person. Often when a person puts their own mike on (without knowing any better – or because they think of it as a ‘nuisance’), they’ll put it half-way down the chest, thinking that ‘that’s good enough.’ So the mike hears the room about as well as it hears them.

Handheld mics

Although there are different types of ‘stick’ mikes, the ones you’ll most often see are made for sound reinforcement duty. These differ from recording-source microphones because they have a passive feedback-cancelling feature built in. The feedback-cancelling area of the microphone is that area beneath the main sound pickup basket.

Never allow anything (other than a mike sock) to cover this feedback-cancelling area. This includes performers’ hands! Here’s where you have to have boldness as ‘the sound guy’ and go tell the performer not to choke up on the mike so much. Tell them that not doing so will make them sound better for your equipment. This short-cuts the performer’s saying something to you like, “Well, I have this same mike and I always hold my mike like this.” Just be gentle but firm and tell them that you’re glad it works for them in their setting – but this is your setting, and you need to have it this way. Just leave them with your thanks and that you’re looking forward to mixing sound for them. Generally they understand that you’re a part of their team and they will help you out. And now you won’t have to manage feedback so aggressively.

When putting a stick mike in a stand clip, it should fit into the clip at a point about halfway up the barrel. Clips are designed this way so as to keep the feedback-cancelling area free.

So how does that little feedback-cancelling space work? Remember that feedback generally occurs from reinforced, reflected sound. This space allows sound waves that would otherwise cause feedback to enter from the back of the pickup area. These sound waves enter the mike out of phase with the sound entering the front of the mike and so cancel out any potential feedback.

Micing instruments

Acoustic Guitars and string instruments:
Try to determine how the performer will be working. Most performers will naturally work within a specific arc when using an acoustic guitar or strings. The sweetest spot for the mike is aimed at the sound hole, with the mike ‘looking’ at the base of the guitar, away from the strings. This maximizes the totality and roundness of the guitar sound, while cutting down on ‘string squeak’.

Brass:
The most successful setups I’ve seen and used are to use a robust mike placed about 2 feet away, and aimed right at the center of the bell. The mike should be `looking’ right down the throat of the instrument.

Woodwinds:
Belled instruments are milked just like brass, while flutes are miked at 45° off the whistle end of the flute. Make sure that the performer won’t be turning too far into the mike so that you end up with plosives (puff sounds) from their playing.

Drums:
Drums don’t need super-high-quality mikes (dynamics do just fine) for things like the snare, toms, cymbal, and high-hat. Mike directly overhead of the drum surface if possible. Mike the high-hat and cymbal slightly off to the side (think center of the main span) but overhead. If you can afford a bass or kick mike, here’s the place to spend the money, as you need something that can withstand the sound pressure pulses. Often the kick mike manufacturer has a recommended spot for their mike, so refer to that. If that info’s missing, start at about 30° off-axis and less than a foot away. Have the drummer kick the drum and adjust as necessary.

Podium Mikes:
These are always a guess, because they often are selected for aesthetic reasons. Too often they end up being dynamic mikes (because of the price; at least they always seem to work) but they tend to be low-gain. A current trend is to use these expensive cute little condenser mics on long sticks. When using these, make sure of your mounting! Podiums can shake and these can be knocked off. They’ll usually stand the fall, but it won’t look good having to go up there and fasten the mic back on the podium.

The best place to set up a podium mike is to one side of the speaker, with the mike arm turned about 45° and aiming the mike head right at where the speaker will be. Any more or less becomes a nuisance: if the mike is right in front of the speaker, then all the audience will see is this big round dot in the middle of the speaker’s face. If the mike is too far to the side, then you have a problem with mike picking up the room and not the speaker.

Here’s a  hint: If your speaker is right-handed, his water glass will be to his right, if it’s not stored below in the lectern. So you set up the mike on the left. And vice versa.

Converter boxes:
These are included with miking because you never know what you’re going to get on the other side of a converter box. It can be everything from an electric guitar’s effects box to keyboards.

Converter boxes are also a typical source of system ground loops, sometimes called “hum.” When trying to get rid of a ground loop, always unplug the convert box, changing cables first; THEN change the converter box. This is because the cable usually gets yanked hard and often when it’s connected to a converter box.

Ground Loops:
These have to be included with mics and converter boxes because we’re using sources that will require high gain. So what is a ground loop? It occurs when a source ground becomes disconnected from earth ground. Power-line signals than can be impressed across the audio cable, and you get hum.

Even so, there’s a difference: a ground loop will have multiples and sub-multiples of 60 Hz in it, and the sound will be raspy. A hum can come from literally anything: an amplifier that’s not properly balanced or from string resonance in an electric guitar, for example. This last thing can drive you crazy. I’ve seen footsteps on the stage cause string resonance.

 

Homework:

(Same as last session. Read on.)

Find yourself a copy of some ‘classic’ music and listen to how the sound crew put together the three-dimensional stage of sound. Find something that matches your tastes and give it a good, deep listen with your eyes closed. Some examples would be:

  • Classical and symphonic music from most any era
  • Jazz music from any era up to the 80’s
  • Rock/Pop from any era up to the 80’s
  • Vocals from any era up to the 80’s

So now do something different: find a well-produced piece from, oh, let’s say the Disco era. (Yes, go ahead and laugh.) But – listen closely to any Bee Gees album and you find several things: Heavy rhythm, heavy bass, clean sounding drum kit, lots of guitar and keyboard in the mix, super-clean vocals. Every voice and instrument is distinct.

But notice something: It’s INTELLIGIBLE!

Now pick up most any later-produced “rock” or “grunge” piece and try to sort out the vocals. Try to sort out the individual instruments.

Harder than you thought? You’re hearing the result of an indifferent mix, the lack of any art in sound mixing. The result of “well we just recorded it, make us an air cut with the remainder of the 2 hours we paid you for”. Now go back to the Bee Gees and listen again. You can hear the space. Compare with the “grunge” again. Sound like it was recorded in a parking garage?

Now you’re getting it.

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