K2 - User Guide - First-time setup

Congratulations on receiving your new pair of K2! Use this guide to learn about pairing K2 with your preferred device and charging the battery.

What's included in the box

  • K2 headphones
  • USB-C cable
  • Owners manual
  • Warnings Folder

Before getting started

The headphones will likely have some existing battery charge, however it is recommended to fully charge K2 before using it for the first time.  

Turning K2 on or off

Press (hold) the button for 2 seconds until the white light is blinking and you hear "On".

If you want to turn off your K2 then press (hold) the button for five seconds until the white light turns off and you hear "Off".

Pairing with a device

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Hold the button on your K2 for 2 seconds to turn it on. The white flash means that your headphones are now turned on and ready to pair. 

Open the Bluetooth settings on your device and wait for K2 and the device to locate each other, then select Sudio K2 when it appears in the list. Once connected, you will hear "Connected".

Charging the battery

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K2 has one built-in battery in the headphones.

K2 is charged with a USB-C cable. It is recommended to use the USB-C cable that's included in the package, but the headphones may be compatible with third-party USB-C cables as well.

K2 - User guide - Connectivity & Pairing

Pairing K2 with a device

  1. Hold the button on your K2 for 2 seconds. The white flash means that your headphones are now turned on and ready to pair. 
  2. Go into the Bluetooth settings on your device. 
    • For iOS (iPhone), go to the Settings app and select Bluetooth.
    • For Android, go to the Settings app, then select Connections followed by Bluetooth.
    • For Windows 10, click on the Start button, select Settings followed by Devices, and then Bluetooth and other devices.
    • For macOS, go to the System Preferences app and select Bluetooth.
  3. Locate and select Sudio K2 in the Bluetooth list on your device.
  4. Your Sudio K2 is now paired with your device.
  5. To turn off your headphones, hold the middle button for 5 seconds. The white light will turn off, this means the earphones are now turned off.

Device compatibility

K2 uses Bluetooth version 5.3 which is compatible with a wide range of Bluetooth devices. The paired device does not need to be the same version, but similar versions are more likely to maintain a strong connection. 

Signal interference

Some wireless devices may interfere with each others' signals, such as WiFi-routers, smartwatches, other Bluetooth devices, etc. If they operate within the same frequency, you may experience interference such as dropped sound and glitching. The easiest way to locate the cause of interference is by maintaining one connection between devices at the same time or taking your K2 and connected device outdoors to see if the interference clears.

K2 can be up to a maximum of 10 meters (49 ft) from the paired device, but the connection may break if they are blocked by walls or similar objects. 

K2 - User guide - Touch controls

K2 has a touch panel that allow you to control certain features on your paired device.

Music/video playback

  • Tap once on the touch panel to pause/play music.
  • Tap twice on the touch panel to go to the next song.
  • Tap three times on the touch panel to go back to the previous song.


  • Hold your finger for 2 seconds on the touch panel to turn up the volume. 
  • Hold your finger for 3 seconds on the touch panel to turn down the volume. 

Incoming phone calls

  • Tap once on the touch panel to accept a phone call
  • Tap twice on the touch panel to hang up or to reject an incoming phone call


  • Press (hold) the button for 2 seconds until the white light is blinking to power on your K2. 
  • Press (hold) the button for 5 seconds until the light turns off to power off your K2. 

Active Noise Cancellation (ANC)

  • Press (hold) the button for 2 seconds after the headphone have turned on to turn on the ANC.
  • Press (hold) the button for 2 seconds to turn off the ANC.

K2 - User guide - Factory reset

If K2 starts behaving unexpectedly, or if you wish to remove the connection between K2 and the connected device, you can perform a factory reset to restore your Sudio K2 to its original settings. This will reset the connection between your paired devices.

  1. Turn off the K2 by pressing (holding) the button for 4 seconds until you hear "Off". 
  2. Press (hold) on the button again for 10 seconds until the light blinks white twice and you hear 2 clicks. 
  3. The reset is now complete. 

When you hear 🔈 Ready to pair, proceed to pair K2 with your Bluetooth device.


K2 - User guide - Battery levels and management

K2 has one built-in battery in the headphones.

Charging and play times

The headphones can be used for approximately 60 hours on one charge (27 hours with the ANC on).

The battery takes approximately 90 minutes to fully charge. K2 does not support quick charge.

Charging methods

K2 can be charged with a USB-C cable included in the packaging. 

We recommend using the Sudio cable included in the package, however, other third-party USB-C cables may be compatible too.

Battery level indicators

Headphones (no cable inserted)

When the battery level is extremely low (0-10%), the LED light indicator on the headphones will start flashing orange.

Battery life status will be indicated on your smartphone for iOS and most Android devices. Since phone manufacturers have various Android devices that work differently, you can also download various battery apps on the Google Play Store.

Headphones (with cable inserted and charging)

  • Amber light - 0-99% battery charged
  • White fixed light - 100% battery charged

K2 - User guide - Download PDF version
K2 - Features - Active Noise Cancellation (ANC)

K2 features two audio modes that let you decide what you want to hear - and what you don't want to hear. These two modes are called Active Noise Cancellation (ANC), and Normal (Off) mode.

The Active Noise Cancellation (ANC) mode in K2 reduces outside noise which allows you to fully immerse yourself in your own world.

How to switch between the modes

The headphones are in Normal (Off) mode by default, where background noise is neither reduced nor amplified. By pressing the button on the K2 for 2 seconds when they are turned on, you can turn on the ANC. Press on the button again for 2 seconds to turn ANC off.

How does Active Noise Cancellation (ANC) work?

The mechanics behind Active Noise Cancellation is in its name. The built-in microphones on K2 listen to the noise outside and inside the headphones while using the speaker to emit the same noise - but inverted - which reduces the outside noise nearly entirely. K2 uses Hybrid ANC technology, which is a combination of Feed Forward and Feedback ANC technology.