Six Audio Mistakes That Cost Clean Speech on Air and in the Room

The most common mistake I see on set is a microphone picked from a shelf before anyone has looked at the space. A cardioid that sounds lovely in a quiet edit suite can pick up every reflection from a bare studio wall, and a lavalier that suits a seated interview will rustle against a presenter who moves around a set. Audio is not my daily trade, since I rig cameras, but I stand next to our audio engineers often enough to know that the room decides a lot of the plan.

Walk the space first. Note hard surfaces, air handling, lighting rigs that hum and the distance between talent and the nearest boom position. Then choose the capsule type and pattern to fit what you found, not what you already own. A short written microphone plan, agreed with the producer before the day, saves arguments on the morning and keeps everyone looking at the same picture of how the speech will be captured.

• Walk the room before choosing any microphone
• Note hard walls, hum and noisy fittings
• Agree a written microphone plan beforehand

Distance is the quiet culprit behind thin, echoey dialogue. Every time the gap between mouth and capsule doubles, the voice loses level against the room, and no amount of gain later brings back the intimacy. Crews often hide a microphone out of shot, then discover that hiding it cost them clarity. A boom held just above the frame line, or a lavalier clipped at the breastbone, will nearly always beat a clever concealed position.

Camera and sound have to negotiate here. When I frame a shot I try to tell the audio team early how wide the lens will be, so they know how close the boom can sit. If the framing changes at the last minute, the microphone position should be reviewed too. A few centimetres of room tone you never wanted is far harder to remove than a boom shadow you could have lit away.

• Keep capsules close to the speaker's mouth
• Tell the audio team the lens width early
• Review mic positions whenever framing changes

Meters tell you level; they do not tell you whether the sound is good. I have watched a perfectly healthy needle sit beside a mix full of air-conditioning rumble, a clothing rustle or a faint buzz from a dimmer. Someone has to listen on proper closed-back headphones, throughout the take, not just at line-up. That listening is a job in its own right and should not be given to whoever happens to be free.

Monitor loudspeakers in the gallery have their own trap. A mix balanced loudly can seem fine until it reaches a viewer at living-room volume, where quiet words vanish. Check the programme at a modest level as well as a loud one. If the show also plays in a venue, listen from the audience side at least once. What the engineer hears at the desk is a good guide, never the whole picture.

• Assign one person to listen on headphones throughout
• Check the mix at a low listening level too
• Listen from the audience side at live events

Gain set too low and later boosted brings up noise; gain set too high clips and cannot be repaired. Many problems that people blame on a microphone are really a gain structure that was never thought through from preamp to desk to recorder. Set levels with the real talent speaking at their natural volume, not with a crew member reading a test line quietly, because people speak differently once the cameras are rolling.

Leave headroom. Speakers laugh, lean in and raise their voices when a discussion warms up, and a limiter is a safety net, not a plan. Keep a note of the settings used so a second session can match the first. On live shows, where there is no chance to retake, agree a nominal operating level with the engineer and keep every source consistent with it from the first rehearsal to the last segment.

• Set levels with real talent at natural volume
• Leave headroom for laughter and raised voices
• Write down gain settings for repeat sessions

Wireless microphones fail in predictable ways: flat batteries, interference in a crowded radio environment, a transmitter pack slipping on a costume. None of these is exotic, and nearly all show up in a proper walk-through. Yet teams often run a single quick test in the green room and call it done. Test each unit where the talent will actually perform, including the corners of the set and any route they walk between positions.

Fresh batteries at the start of every day cost very little compared with a dropout during an interview. Label each transmitter with its channel, keep spares charged and within reach, and brief the talent on what to do if something goes wrong. A short, calm instruction such as keeping speaking while a technician swaps a pack protects the take far better than a full stop and apology.

• Test every radio mic across the whole performance area
• Start each day with fresh batteries and charged spares
• Label transmitters by channel and keep spares close

The pattern behind most of these mistakes is timing. Audio gets the final ten minutes before recording, after lighting and camera have taken their share, and every problem then has to be solved in a hurry. Give it its own slot in the running order, with a line check, a room-tone recording and a short rehearsal of the trickiest moments. The producer loses a little time up front and gains a good deal in the edit.

Record a minute of room tone at every location; editors need it to patch gaps smoothly. Keep a clean backup recording when the budget and the signal chain allow it. And speak to the audio engineer as early as the camera supervisor and the lighting designer, because the three plans share the same floor, the same rigging points and the same few metres around the talent.

• Give audio a protected slot in the running order
• Record room tone at each location
• Involve the audio engineer at the planning stage