Line & mike levels and more audio tales from the darkside…

I’ve always said that audio is just as important as video when producing visual stories. If an audience has to struggle to hear sound, they will tune out and turn off (or skip to another site).

How you get sound into a camera (or story) can vary.

The most obvious (and worst) mike is the built-in mike on the camera. Generally this is an omni-directional mike. It picks up sound from every direction…with the closest noises recorded at the highest level (don’t cough – oh no!). That means the person holding the camera trumps the person being interviewed. (NOTE: if you MUST do an interview w/an on-camera mike, get in as close as you can. That means FILL THE FRAME with their face (no – DON”T zoom). Put them in an environment where there is NO distracting background audio. Even an air conditioner or dog barking in the background can ruin your interview audio. I told my students to reach out and touch the person they were going to interview…and back up no further than that.)

Lesson #1
Don’t purchase a camera that only has an on-board mike.

Not to worry – there is a workaround. If you’re into simple editing and have patience.
Just pick up one of those little digital audio recorders (I got mine for about $65). You can either place it near your subject (or noise source) or plug in a clip-on mike and tack that onto your willing subject. Much cleaner audio. Problem is, you have to match up or synch(chronize) the audio in a non-linear editing program.

Which gets us into what a clapboard really is. It’s not just something to bang around in front of the camera or make note of which scene and take you are up to. The matched visual of the clapper hitting the board along with the ensuing sound are what enable you to synch up audio and video later. (First workaround – just clap your hands right in front of the lens/camera. The cheapest “clapper” I know of/have used.)

Failing that…hope that your subject at some point used a “P” or a “B” or even a “W.” Those consonants have very distinctive audio cues…
The “B” sound can ONLY be made by putting your lips together and pulling them apart. (Yeah – just TRY to say baby without putting your lips together).
The “P” sound is similar. Lips begin pressed together.
“B” sucks in…”P” pushes out.
And if your interview subject says “welcome” or “why” or “whatever…”, the lips once again begin pressed together, but then open up and down.
Find those B, P, and W words and then try to match the lip action with the sound. Piece of cake. (And you can try it with other letters of the alphabet too – these have just been easiest for me.)

Lesson #2
Moving along…let’s say you were smart (or lucky) and have a camera with audio inputs. Today’s camera basically use two types of audio connectors. XLR (professional) and 3.5mm (mini-jack, consumer & prosumer).

(First let’s get the dirty little language lesson out of the way. There are male and female connectors. The boys have prongs. The girls have holes. End of lesson.)

The mini-jacks come in either stereo/two channel (left & right) or mono/one channel. This is a tiny connector you plug into your camera. Beware: it can come loose easily.

XLRs are grounded and balanced and locked. This means they are hot swappable (no noise when plugging in/unplugging). A balanced cable allows you to run longer cable runs without noise. And locked? The mini-jack can be pulled free but an XLR locks into place…no fear of losing audio if the cable pulls loose.

XLRs don’t come in stereo or mono. Most cameras with XLR inputs have two. Channel one and channel two. You can choose to record on both channels with your on-board mike, or plus in another mike and record from the camera on one channel and the plug-in on another…or even plug in two mikes and record separate sound on each channel. Wow. (That’s professional for ya.)

Now thanks to the wonderful world of adapters (and Radio Shack and its kin), you can actually interchange mini-jack and XLR mikes. There are screw-on interfaces which allow you to run a mini-jack out of your camera and plug XLR cables into it. And you can go the other way – although why, I can’t imagine.

OK – so now you know what kind of input you have on your camera. Hopefully you know if it is stereo or mono. Final step: what mike are ya gonna use?

Lesson #3
Microphones. I’m going to overgeneralize, just to keep this simple.

First – there are wired and wireless mikes. Well, not mikes, but systems.

A wired mike uses a cable to plug into the camera. You are limited in range to the length of your mike cable.

A wireless mike is actually a transmitter with a mike plugged into it and a receiver, which is plugged into the camera. This increases the range of the mike from the length of a cable to the distance the signal can be received.

So what exactly ARE you gonna plug into your camera (or wireless transmitter)?

Shotgun mike.
Stick mike.
Clip-on mike.

One. Two. Three.

A stick mike is the tool of choice for many TV cameramen/reporters. It is omni-directional – it picks up sound from nearly every direction. It allows the user to choose who/where they will point it. It allows the user to control the interview by pulling the mike back as needed. And most stick mikes (the professional grade again) are solidly built. My Electovoice 635 could be used as a hammer.

Clip-on mike, aka lavalier microphone. The word “lavalier” is French in origin and refers to a pendant worn around the neck on a chain. The original lav mikes were placed around the neck of the interview subject with a cord. Today’s lav mikes are tiny and can be clipped on unobtrusively on an interview subject (or reporter). Most lavs are omnidirectional.

Shotgun mike. Now this has always confused me. A shotgun actually sprays out it’s projectiles in a widening pattern. However, a shotgun mike is a unidirectional mike. It has a narrow range it can pick up audio from. Perfect for aiming across a room at someone speaking or getting interviews with several subjects in a fairly noisy venue.

Which do you use in which situation?

1. They can all be used for interviews.
2. The stick and shotgun mikes allow you to interview several people at the same time, just by pointing the mike at the person you want to hear speaking.
3. The lav mike can only be pinned on to one person at a time.
4. The stick and shotgun allow you to control the interview by pulling the mike away from the interview subject and asking new questions. A lav mike gives the power to the subject, who can just ramble on.
5. Stick mikes are generally solidly built and can outlast cameras.
6. Lav mikes are generally be delicate.
7. Shotguns can be used on booms (long poles) and operated by a sound person, who points it at the desired sound source.
8. Generally speaking, stick mikes are least expensive, followed by lavs, followed by shotguns.

As usual, there are exceptions to all generalizations.

Um…in a later posting I’ll get into why cost and quality go hand in hand. Also why prosumer/professional cameras are a better choice simply because they allow you to control/mix audio coming into the camera.

Oh – and mike and line?

Those are refences to what level (how high/low) the audio levels are that come into the camera. Mike level is lower. Line level is high – at times overwhelmingly high. If you feed a line level into a mike input, you’re gonna get blown away. Distortion. Most consumer cameras don’t even need to worry about this…unless you for some reason want to link into an audio mixer to take a feed. A very unlikely scenario for the average consumer. Even potting (aka turning) the sound all of the way down with using a mixer won’t help. But professional and prosumer cameras often come with a switch that allows you to choose which level you want the audio feeding in at (mike/line). Plus controls to pot it up or down.

More later…I feel a roadtrip coming on…


2 thoughts on “Line & mike levels and more audio tales from the darkside…

  1. I bring it up, have them “make the connection” and let them wallow in it on their own…best bet is to keep moving. I also use the newsie term “grab your sticks and spread your legs,” for set up your tripod. The older kids tended to keep the younger ones in line…they were already on the inside and kind of let the young ‘uns know it was NOT cool to carry on about it.

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