The deposition signal chain that prevents bad audio

Bad audio kills a deposition video.

If the audio is unusable, the video is unusable. An attorney can read a transcript, but nobody can watch a video they can't hear, and that asymmetry is why audio deserves more of your attention than anything else in the bag. Unrecoverable audio is the single most expensive mistake in legal video, and it is almost always preventable.

The reference signal chain.

A lavalier microphone on each speaker feeds the mixer, the mixer feeds the camera audio input, and the mixer feeds a backup recorder at the same time. The mixer is the redundancy point, because the camera and the backup recorder are each capturing that same mixed signal independently. If the camera fails you still have audio, and if the backup fails you still have audio. If both fail on the same day, something has gone badly wrong and you are about to have a hard conversation.

Mic placement actually matters.

Put the lavalier on the lapel, roughly six inches below the collarbone and off-axis from the mouth. A boundary microphone on the table works as a fallback for the witness only, since counsel are already covered by their own lavaliers. When a deponent leaves the room, cut the microphone, save the file, and restart cleanly when they come back.

Gain staging is the discipline.

Set the mixer at unity, bring channel gain up until it peaks around -12 dB, and match the camera input to the mixer's output reference level. Do all of that once, before the witness arrives, and then verify it on every break. The most common signal-chain failure isn't equipment at all, it's somebody bumping a knob during the day, and that somebody is usually you.

The three errors that kill the record.

The first is running with no backup recorder. The second is leaving camera audio on auto-gain, which sounds perfectly fine in the room and turns out unusable on playback. The third is a microphone battery you didn't change at the morning break, which dies around two in the afternoon and goes unnoticed until you sit down to review.

Reading the meters during the deposition.

Glance at the mixer meters every five minutes and at the camera audio meter on every break. After you go back on the record, listen on closed-back headphones for at least the first two minutes. If something has changed, you want to find out inside of two minutes rather than at the end of the day.

Remote is a different problem, not an easier one.

Everything above assumes you own the chain from end to end. On a remote deposition you own the last link and nothing before it, because the witness's audio has already passed through a laptop microphone, noise suppression, and a variable network before it ever reaches you, and none of that is fixable afterward. We work through the remote-specific version of this discipline in our guide to remote depositions over Zoom.

What happens to the audio after the day ends.

The redundancy you built in the room is worthless if the file only exists in one place that night. Both the backup recorder's file and the camera master belong in the archive, and both are covered by the 1-2-3 archival rule. Recovering a deposition from a backup track you never copied off the recorder is a story every experienced member has heard, and none of them tell it about themselves twice.

Where this is taught.

The signal chain is module six of the CDVS curriculum, where we work through microphones, mixers, redundancy, gain staging, and these same failure modes hands-on. If you're still deciding whether to buy in, our Deposition Video 101 course covers the gear list and what it costs, and it's free!