6 Common Misconceptions about Audio for Video

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When it comes to producing audio for video and purchasing relevant equipment, one can make many mistakes based upon misinformation and misguided (though well-intentioned) recommendations. Whether you’re relatively new to the audio side of things or you just want to make sure you haven’t missed an important tip, it’s worth reviewing these six common misconceptions about audio for video.

#1: Wireless Is Better Than Wired

Verdict: Misleading

In the context of audio for video, you cannot rightfully state that wireless is better than wired or vice versa. Each method is better for different things. For sound quality and reliability, wired connectivity is best because it is exempt from the additional interference, processing, codecs, and sonic limitations that are unique to wireless technologies. For flexibility, wireless wins because of the obvious… it’s untethered. Imagine the tangled mess a theater production would present if each cast member had a cable from their clip-on mic running all the way back to the mixing console.

#2: Mic Quality is More Important than Mic Placement

Verdict: False

This is a classic and ongoing mistake; spending more money on a better microphone instead of spending more time on mic placement. For example, when recording dialogue, a $50 lavalier mic at the subject’s sternum will sound far better than a $1,000 shotgun mic 15' away. Research and experiment to determine the best position for the mic you have, and if you’re about to purchase a different mic, ask about its optimal placement. For speech clarity, proximity is usually preferred over distance, and there are other important subtleties such as the mic’s polar pattern and angle of orientation. However, put the mic too close to the person’s mouth and you’ll get too much low-end buildup, breathing, and sibilance (e.g. shrill “S” sounds).

#3: Shotgun Mics Zoom in on Sound

Verdict: False

Although I’m sure someone made the analogy because it’s a reference that most people would understand, it leaves you with the wrong impression. Considering that most shotgun mics pick up less sound from their sides—seemingly narrowing the audio field of focus—it’s easy to see how the comparison was born. However, concluding that shotgun mics can “zoom in” on distant sound sources and ignore the surrounding environment… well, that’s demonstrably wrong.

Another incorrect assumption about shotgun mics is that they only capture sound in front of them, leading many people to use them improperly. For example, think about shooting a scene in a kitchen with reflective surfaces and a low ceiling. From the videographer’s perspective, it would be good to have a shotgun mic held up near the ceiling, pointing down at the talent, well out of the frame. The resulting sound quality would be a big disappointment, though. Due to the supercardioid and lobar polar patterns of most shotgun mics—they still accept some sound from the sides and rear—you’d be picking up too much room ambience and indirect sound from the ceiling. Though shotgun mics are great in outdoor environments and acoustically treated rooms, a better mic choice in this case would be a lapel mic or a hypercardioid pencil condenser mic. In general, pencil condensers are shorter than shotgun mics (easier to keep away from the ceiling while remaining out of the shot), and one with a hypercardioid pattern would have less coloration from room reflections (though pencil condensers are less directional than shotguns).

#4: Just Check the Meters

Verdict: False

This is one of the most tragic and frequent mistakes of recording audio for video. Far too often, people assume that if audio meters are showing signal, it’s good to record. No, no, no. Audio meters on cameras and portable recorders only show signal level; they in no way tell you if it actually sounds good. Just like you obviously want to see the video you’re shooting, you should want to hear the sound you’re recording. It’s the only way to find out if it’s too thin, muddy, reverberant, or distorted. Do not trust your eyes over your ears; ALWAYS listen to what you’re recording.

How should you do it? Use headphones, not the built-in speaker on your camera or portable recorder, and connect the headphones to your camera/recorder. For cameras that don’t have a headphone jack, you can get an HDMI to VGA adapter that has a 3.5mm audio output—Comprehensive makes versions with HDMI Type-C or HDMI Type-D to suit different cameras. Armed with the correct adapter, you’d connect it to your camera’s corresponding HDMI output, then plug your headphones into the audio port on the adapter. Success! You can listen, listen, listen. It’s still a good habit to check your audio meters, but don’t rely solely on them. LISTEN!

#5: Record as Hot as You Can Without Clipping

Verdict: False

The idea that you should record with your input levels as hot as possible (without clipping) came from early days of digital recording, as engineers were transitioning from analog tape to digital recorders. When tracking to analog tape, it is common practice to record quite hot for two reasons. First, doing so helps overcome the inherent noise floor and tape hiss. Second, the technique of pushing beyond the “ceiling” of analog tape is known to create gentle compression and add pleasing harmonic distortion, though going too far will yield an overly distorted sound. However, digital recording systems have a lower noise floor with no tape hiss, and pushing them beyond the “ceiling” of digital (0 dBFS) yields only unpleasant distortion with no gentle compression or lovely harmonics. So, it’s best to leave some headroom when recording to your camera, mobile device, portable audio recorder, or computer; many people recommend average input levels from -20 to -10 dB on the digital meters of your device.

#6: You Can Always Replace the Audio Later

Verdict: Misleading

Though dialogue, Foley, and sound effects are often recorded in a studio (long after shooting video or film) to replace or bolster some of the on-set audio, doing so is expensive, time consuming, and sometimes impossible. What if poorly recorded, unusable on-set dialogue can’t be replaced later because the actor unfortunately dies (think Heath Ledger and The Dark Knight)? What if there isn’t enough money in the budget to recreate all the sound from the jungle, beach, subway, and restaurant scenes in the movie—you know, because the location recordings were overly distorted due to the sound recordist setting levels too hot and only checking the meters? Epic fail, that’s what. So remember, the better the audio recorded on location, the better and easier the audio post-production process will be.

Conclusion

I hope reading this cleared up some basic, yet significant points or reinforced your sincerely held beliefs. Perhaps you’re thinking, “Hmm, I’ve learned something, but it seems the more I know, the more I realize I don’t know.” Yes, that’s a normal, healthy thought. If you find yourself wanting to know even more, start with this video and check out additional related content here. We’re all about spreading knowledge, so share your wisdom in the Comments section, below.

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