Improving Interview Audio with Simple Microphone Placement

Why placement beats pricey kit

Most people who record interviews assume that better sound means better equipment. It rarely does. A modest microphone placed thoughtfully will comfortably outperform an expensive one that is pointed at the wrong part of a speaker's face. Placement affects everything: how much breath noise you capture, whether plosives thump the capsule, how steady your levels stay when someone leans forward or turns their head, and how much of the room you hear around the voice.

The good news is that the fixes are free and take about two minutes. You do not need to understand polar patterns or signal chains in any depth. You need to understand where the microphone is pointing, how far away it sits, and what it is physically attached to. Get those three things right and the rest of the job becomes much easier.

Aim slightly past the mouth, not at it

The single most useful habit is to position the microphone off-axis. Rather than pointing the capsule straight down the throat of the person speaking, angle it so the diaphragm looks past the mouth, roughly towards the corner of the lips or the cheekbone. Ten to twenty degrees of offset is usually enough.

Why does this help? Plosives, the hard p, b and t sounds, produce a concentrated blast of air. Fired directly at a capsule, that blast hits the diaphragm as a low-frequency thump. Move the microphone a little to one side and the puff of air travels past it rather than into it, while the voice itself, which radiates in a broad pattern, still arrives loud and clear.

The same trick softens sibilance. Sharp s and sh sounds are directional and beam forward, so stepping out of their path takes the edge off without dulling the rest of the speech. You will notice the benefit immediately in the raw recording, which saves a great deal of fiddling later.

Find a distance that suits the room

Distance is a balancing act. Too close and you capture mouth noise, plosives and every lip smack. Too far and the room takes over, the voice sounds thin, and you have to raise the gain, which lifts the background noise with it.

For a typical untreated room, a working range is 15 to 25 centimetres from the speaker's mouth, angled off-axis as described. In a very live space with bare walls and hard floors, push towards the far end of that range and consider hanging a duvet or blanket behind the speaker. In a soft, furnished room with carpets and curtains, you can move closer and enjoy a fuller, more intimate tone.

If you are working with a handheld recorder or a phone, the same logic applies. Hold it slightly to one side of the mouth and a little below chin height, rather than directly in front. Chin height reduces the amount of nasal and breath noise that reaches the microphone.

Keep the microphone still, and keep the speaker still

Movement is the enemy of consistent levels. If a speaker gestures with the microphone in hand, or rocks back and forth in a chair, the distance between mouth and capsule changes constantly. The result is audio that swells and dips, which is tiring to listen to and awkward to fix.

• Use a boom arm or desk stand so the microphone stays where you put it.
• Ask the interviewee to sit back and settle before you start, then bring the microphone to them.
• If they must hold it, show them how to rest their elbow on the table for stability.
• Note which way they tend to turn when thinking, and angle the microphone slightly towards that side.

A shock mount is worth having if your microphone sits on a hard surface, because it isolates the capsule from knocks and from vibrations travelling up through the desk. A cheap mount often solves more problems than a new microphone.

Quietening bumps, rustling and table noise

Handling noise is the most common complaint in interview recordings, and it is almost always a placement problem rather than a fault. Rustling comes from clothing brushing the cable, from a hand shifting on the body of the microphone, or from a notebook or coffee cup being nudged on the same surface as the stand.

• Dress the cable so it hangs with a gentle loop of slack, taped or clipped to the stand, so tugs do not reach the microphone.
• Keep the microphone off the same surface as mugs, papers and tapping fingers. A separate small table works wonders.
• Ask the speaker to avoid fiddling with jewellery, lanyards or zips near the microphone.
• Use a pop filter or foam windshield, but treat it as a backup rather than a substitute for good angle and distance.

A gentle low-cut filter, often labelled as a high-pass, set somewhere around 80 to 100 Hz, will remove rumble from footsteps, traffic and desk knocks without touching the body of a human voice. Most recorders and interfaces have one, and it is usually worth engaging for speech.

Set levels, then test for real

Before the conversation begins, set your gain so that normal speech peaks somewhere around -12 to -6 dBFS. That leaves enough headroom for laughter, a sudden emphatic point, or someone leaning in. Record a thirty-second test and listen back on headphones, not on a laptop speaker, which hides almost everything you need to hear.

During the test, ask your interviewee to say a few of the phrases they are likely to use, including any difficult words or names. Listen specifically for plosives on p and b sounds, sibilance on s, and any rustle when they shift in their seat. Adjust the angle slightly and repeat. Two minutes of this kind of checking will spare you an hour of repair work, and it means you can concentrate on the conversation itself rather than worrying about the recording.