Microphones: which one you actually need

The first question people ask after "why does my audio sound bad" is "which mic should I buy". The answer depends on what you film, more than on your budget. Sometimes the right answer is none.

When the built-in mic is enough

The microphone in your phone is decent. It's designed for a voice at close range, and if the phone is 20–30 centimetres from your mouth, the recording will be clean and clear. That covers close-ups, talking to camera, stories, quick front-camera videos.

It breaks down in two situations. The phone is far away, on a tripod a metre and a half off: the voice gets lost in the room. And filming outdoors: wind on a phone mic turns into a roar. You can hardly remove it afterwards; the only things that help are a windshield and a spot sheltered from the wind.

If you film close and indoors, start with the built-in mic. Light is the next purchase, once the sound is sorted.

Lavalier

A small clip-on mic that attaches to your clothing near the chest. This is the go-to mic for talking videos when you're far from the camera. Your voice stays at a constant distance from the capsule, you can move around, and the sound doesn't change.

A wired lav that plugs into the phone is the cheapest option. The cable limits your movement, but the sound is good. A wireless one has a transmitter on you and a receiver in the phone, so you move freely, but it costs more. For reviews, desk talks and interviews, a wireless lav solves almost everything.

Attach it at chest level, a hand's width below the collarbone, capsule pointing up towards your mouth. That puts it roughly 15–20 centimetres from your mouth, which is right. Make sure fabric isn't rubbing against it, and don't turn your head too far to the side or the voice drops off.

The connector: check before you buy

The most frustrating purchase is a lav the phone can't see. Wired mics made for phones have a four-contact plug called TRRS, with three rings on it. A regular three-contact mic plug with two rings (TRS) won't work in a phone. If your phone has no headphone socket, you need a Lightning or USB-C adapter that supports a microphone rather than headphones only. Check that in the product description before paying.

On-camera shotgun

A directional mic that mounts on top of the phone or a rig. It picks up what it's pointed at and hears less from the sides. You need it when you're filming handheld and the subject isn't you: an unboxing, food, a walk, a workshop. A lav is awkward there, and the built-in mic catches too much room.

For talking to camera from more than a metre away, a shotgun is worse than a lav: it's still further from your mouth.

Desktop and USB

A large mic on a stand or a desk, plugged into a computer or into the phone via an adapter. For voiceover, podcasts, narrating over footage. It's usually not in shot, so you can put it close, 15–20 centimetres from your mouth, slightly to the side or above your lips. The sound comes out fuller than any other option.

It's good for voiceover if the room is quiet and dead: this kind of mic picks up the room more than a lav does. If you're always on camera, you don't need it.

Windshield and pop filter

Two cheap things that save recordings. A foam or furry windshield slips over the mic and tames wind outdoors. A pop filter, the mesh in front of a desktop mic, kills the puffs of air on "p" and "b". If you don't have one, place the mic slightly to the side of your mouth so the air goes past the capsule.

Earphones with a mic

The free option everyone already has. Wired earphones with the mic on the cable: the mic ends up near your collarbone, like a lav, and the sound is noticeably better than a phone a metre away. Wireless earbuds work too, but many of them compress the voice and it comes out flat, like a phone call. Test yours: record ten seconds and listen.

Tip. Whatever you choose, listen to it before the shoot. Plug it in, record ten seconds, play it back on headphones. Phones sometimes don't switch to the external mic, and you find out after an hour of recording.

What matters more than the mic

An expensive mic in a room with a lot of echo, a metre from your mouth, sounds worse than cheap earphones at your collarbone in a room with a duvet. The order of importance: distance, then room, then microphone. Sort the first two and even a budget lav will sound noticeably cleaner.

Do this now

• Record the same sentence on your phone 20 centimetres from your mouth and then a metre and a half away. Listen to the difference.
• Plug in earphones with a mic and record the same sentence. Check the phone actually switched to them.
• Decide what you film most often and pick one type of microphone. One, not three.