How to Use a BOYA BY-M1 Mic Without a Battery

The BOYA BY-M1 is one of the most popular cheap lavalier mics. It is the mic I use in my video on this fix. It normally runs on a small LR44 battery. If the battery is dead or missing and you plug the mic straight into a PC, it records nothing, and it is easy to think the mic is broken.

It is not broken. There is a simple fix that costs about a dollar. In this guide I explain why it works, so you can also solve the same problem with other small mics.

Why the mic goes silent without a battery

A microphone like the BY-M1 needs a tiny amount of electricity to work. It can get that power from two places:

The battery, when the switch is on Camera. Most cameras do not send power to the mic, so the battery does the job.
The device it is plugged into, when the switch is on Smartphone. Phones and most computer microphone jacks send a small voltage down the cable. This is called plug-in power.

So without a battery, the mic must be on Smartphone mode and plugged into something that provides plug-in power. A PC's microphone jack does. The only remaining problem is the plug.

The switch on the mic

Camera mode versus Smartphone mode

CameraRuns on the batteryWithout an LR44 battery, nothing is recorded.Silent with no battery

SmartphoneUses plug-in powerPhones and PC mic jacks send a small voltage down the cable.Works with no battery

The plug problem, in plain words

Look at the end of the BY-M1 cable. It has three black rings on it. That type of plug is called TRRS, and it is made for phones, where one plug carries headphone sound and the microphone together.

Many desktop PCs have separate jacks: a pink one for the microphone and a green one for headphones. Those use plugs with two rings, called TRS. If you push a TRRS plug into a pink TRS jack, the microphone signal lands on the wrong contact, and you get silence.

A headset splitter fixes this. It takes the TRRS plug on one side and splits it into a separate microphone plug and headphone plug on the other.

Check your computer's jacks

Do you need the splitter?

Separate pink and green jacksDesktop PC: yesThe pink jack expects a two-ring plug. The splitter converts it.Use the splitter

One jack with a headset iconLaptop combo jack: noIt already accepts three-ring plugs. Plug the mic in directly.Plug straight in

What you need

A BOYA BY-M1 microphone.
A 3.5 mm headset splitter cable with separate microphone and headphone plugs. They are cheap and sold as "headset splitter" or "Y splitter for headset".
A PC with a separate microphone jack, usually pink.

If your laptop has a single combined headphone and mic jack, often marked with a headset icon, you do not need the splitter. That jack already accepts TRRS plugs. Switch the mic to Smartphone mode and plug it in directly.

Steps

Switch the slider on the mic from Camera to Smartphone. This is the step most people miss: in Camera mode the mic needs the battery.
Plug the BY-M1 into the splitter's 3.5 mm socket.
Plug the splitter's microphone plug, the one with the mic icon or a pink band, into your PC's microphone jack. You do not need the headphone plug.
Open Voice Recorder or Sound settings and speak. The level meter should move.

The connection

From mic to PC in four moves

01Smartphone modeSwitch the slider so the mic uses plug-in power.On the mic

02Into the splitterThe three-ring TRRS plug goes in the splitter socket.TRRS

03Mic plug to pinkUse the plug with the mic icon. Ignore the other one.Pink jack

04Select the inputSettings, System, Sound, then pick the microphone.Windows

Set the level so it sounds good

Go to Settings, System, Sound, choose your microphone and open its properties. Set the input volume so your normal speaking voice reaches about two thirds of the meter. If the meter hits the top when you speak loudly, turn it down a little. Clip the mic about a hand's width below your chin, on your shirt, for the clearest sound.

If it still does not record

Check the plug is in the microphone jack, not the headphone jack.
Go to Settings, System, Sound and select the external microphone as your input device.
Make sure the slider is still on Smartphone. It is easy to knock it back.
Try the front and back mic jacks. Front panel jacks on some cases are not connected or are loose.
If you hear a loud hum, the cable may be near a power cable, or the splitter plug is not fully pushed in.

Can I use it with a camera without a battery?

Usually not. Most cameras do not provide plug-in power, so the mic needs its battery in Camera mode. If your camera's manual mentions plug-in power, it may work, but for cameras a fresh LR44 battery is the reliable option.

The short version

Set the BY-M1 to Smartphone mode so it uses your PC's plug-in power, and connect it through a headset splitter to the pink microphone jack. On a laptop with a combined headset jack, plug it straight in.