Sound Track: The Audio Mixer: It's No Contest

by Loren Alldrin
March 1998

Just outside Jerry's garage, a city worker fires up a jackhammer. The noise makes it nearly impossible for Jerry to hear his audio, so he grabs a pair of headphones. Since the only place he can monitor his audio is at his record deck, Jerry attaches a 1/4-inch to 1/8-inch adapter onto his headphone cord and plugs it into the deck. The deck has no headphone level control, and the sound ends up being painfully loud. He perches the headphones halfway off his ear to reduce the volume. His ears are sore and ringing in 20 minutes.

Julie's neighbor begins pruning his trees with a chainsaw, easily drowning out her small speakers. Julie grabs a pair of headphones and plugs them into her audio mixer. Using the mixer's headphone output level control to adjust the volume, she sets a comfortable listening volume. Julie tucks the excess headphone cable alongside the mixer and continues working.

12:35 p.m.
Julie checks some music she recorded at a friend's piano recital, debating whether or not to use it in her video. She recorded the music on a portable stereo; the sound is thin and lacking in bass, and also has noticeable tape hiss. She turns up the mixer's bass EQ controls on the cassette input channels to add fullness to the piano music. Reducing the treble EQ controls lowers the tape hiss to bearable levels. Without affecting any other signal in the mixer, Julie salvages the piano music and dubs it onto her videotape.
Jerry plans to use a similar piece of music, also recorded with his portable cassette deck. With no way to equalize the signal, however, Jerry is stuck with thin sound and lots of tape hiss. He uses the music anyway, hoping no one will notice the lack of fidelity. "After all," Jerry mutters to himself, "it's just music."

2:08 p.m.
Jerry's friend Tom arrives to record some voiceover narration. Tom brings a high-quality vocal mike he uses when singing with his oldies band. Jerry's VCR has an 1/8-inch mike input, so he begins stringing together cables and adapters to match up to Tom's balanced XLR mike. With an XLR to 1/4-inch cable feeding a 1/4-inch to 1/8-inch adapter, Jerry finally gets sound from the mike. He also gets loud AC hum from the cable, as well as hiss from the deck's maxed-out record levels. Again hoping nobody will notice, Jerry and Tom begin recording the narration.
Julie's friend Tina is a radio DJ, and is excited at the prospect of recording voiceover for a video. She brings her favorite mike with her, which Julie attaches to her mixer's XLR input with a balanced 12-foot cable. Bringing up the mixer's input trim halfway, Julie gets crisp, clean audio from Tina's mike. Stopping only to eliminate the occasional popped "p" sound, Julie and Tina record the narration in short order. It sounds great.

3:14 p.m.
Jerry begins putting a music bed under his newly recorded narration. He wants the voiceover to be intelligible but not too loud, so he carefully sets the level of the music as he records it. Jerry doesn't realize that his speakers aren't very accurate, and tend to accentuate the range of frequencies that correspond to the human voice. This makes the voiceover sound loud enough on his speakers, but too quiet on more accurate speakers. When he discovers the error on someone else's system, it's already too late.
Julie owns the same pair of speakers that Jerry does, but is well aware of their sonic shortcomings. Her mixer has a built-in graphic equalizer that she can switch between her record output (going to her deck) and her monitor output (going to her speakers). Julie puts the equalizer in-line with her speakers, and lowers the middle sliders some to compensate for the speakers' strong midrange response. With the speakers sounding more like they should, Julie can be much more certain her audio will sound the same on other systems.

5:22 p.m.
Recording one of his last scenes to the VCR, Jerry has to change his record levels. For the hundredth time that day, he kneels in front of his VCR and adjusts a small knob behind a flip-down panel. Just when he's got the level close to where it needs to be, the scene ends. He rewinds the scene, plays it again and fine-tunes the record level.
Julie hasn't touched the record level controls on her VCR since she bought her mixer. She set both left and right record level controls to the 3 o'clock position, and left them there. Now she makes all her adjustments at the mixer, finding simple fader moves to be much easier than constant fiddling with record levels.
Jerry glances over at his record deck often to check its input level meters. Moving the deck to eye level helped things a bit, but Jerry's neck still gets sore from the constant craning.
Now that Julie has a mixer, she rarely looks at her record deck's input meters. She doesn't need to--the level she sees at her mixer's output meters matches that of her record deck. She calibrated her VCR to the mixer by sending a constant sound through her mixer (she used a flute sound from her son's portable keyboard). She adjusted the mixer's input and output faders until its meter read 0dB, then set the VCR's input level controls to achieve the same 0dB reading. Unless she changes her VCR's input level controls, the meters are a perfect match.

6:58 p.m.
Finished tapes in hand, Julie and Jerry scramble to reach the same overnight delivery drop-box before 7:00 p.m. Jerry is sore, tired and cranky from making so many compromises in the audio quality of his production. Julie is relieved to have her video finished, and is marveling at what a difference her audio mixer made in the whole process.
As they reach for the handle of the drop box in unison, Julie notices the Videomaker/Panasonic Contest label address on Jerry's package. "Hey," Julie says, "you're entering the contest too!"

7:48 p.m.
After talking about their videos over coffee, Jerry finally sees the light. "Julie," he says, "I have got to get an audio mixer!" "But Jerry," Julie replies, "you've got a computer with a sound card. With the right software you've already got an audio mixer."

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