PCM Audio in Windows 10: Configure the Output

Short answer: PCM output in Windows 10

Windows 10 already sends PCM to ordinary speakers, headphones and most USB output devices. The audio engine decodes and mixes sound from apps, then passes uncompressed samples to the device. You can usually adjust three things: the PCM format the device runs at (channels, bit depth and sample rate), the speaker layout, and whether apps may take exclusive control of the device. These options are in the classic Sound control panel. The Settings app links to that panel, but labels and link placement differ between Windows 10 builds and audio drivers.

Set the default format for an output device

• Open the classic Sound dialog. Depending on your build, right-click the speaker icon in the taskbar and choose Sounds, follow the Sound Control Panel link in Sound settings, or press Win+R and run mmsys.cpl.
• On the Playback tab, select your output device and click Properties.
• Open the Advanced tab and choose a value under Default Format, such as 2 channel, 24 bit, 48000 Hz.
• Click Test to confirm playback, then click Apply.
• For multichannel speakers, select the device on the Playback tab and click Configure to choose the speaker layout, if your driver offers this option.

How PCM output works

PCM (pulse-code modulation) stores audio as a series of samples taken at a fixed sample rate, with each sample recorded at a fixed bit depth. CD audio uses 44.1 kHz at 16 bit. Video files and many communication apps commonly use 48 kHz.

By default Windows runs devices in shared mode. In shared mode, the audio engine mixes every app's sound and converts the result to the device's Default Format. If a source uses a different sample rate, Windows resamples it. The Advanced tab also has two exclusive mode options: one lets applications take exclusive control of the device, and the other gives exclusive mode applications priority. When exclusive mode is allowed, an app that supports it, such as some music players and recording software, can open the device in its own format and bypass the mixer. While that app holds the device, other apps may go silent.

The Default Format list is not fixed by Windows. It shows the formats that the device driver reports. Two devices on the same PC can therefore offer different options, and the list may change after a driver update.

Outputs to an AV receiver or TV over HDMI or optical (S/PDIF) work differently. Here an app can send either decoded PCM or an encoded stream such as Dolby Digital or DTS, which the receiver decodes (often called bitstream or passthrough). Some of these devices show a Supported Formats tab that lists the encoded formats and sample rates the connected equipment accepts. Standard optical S/PDIF carries two-channel PCM, so multichannel sound over optical needs a compressed format. HDMI can carry multichannel PCM when both the PC and the receiving device support it.

Choosing settings for common situations

• Video calls and online video: 48 kHz is a common choice because much video and call audio uses it. Setting the output device and the microphone to the same rate can avoid extra conversion.
• Music that is mostly CD-sourced: a 44.1 kHz format avoids resampling that material in shared mode. Whether the difference is audible depends on the recording and your equipment.
• Home theater over HDMI: set the speaker layout under Configure to match your receiver, and choose a multichannel format. Alternatively, let a player that supports passthrough send encoded audio to the receiver.
• Optical connection to a soundbar or receiver: expect stereo PCM. For 5.1 sound, use a player and receiver that both support an encoded format.
• Microphone or other input device: the same Advanced tab is on the Recording tab under the device's Properties. Use a sample rate your recording or call app supports. Adjust the input level on the Levels tab of the same dialog.
• No sound after a change: return to a lower or previously working Default Format. If one app takes over the device and others go silent, clear the exclusive mode options.

Limits and related questions

PCM is uncompressed, but it cannot recover data a source never had. An MP3 or AAC file is decoded to PCM for playback, and its lossy compression remains. Likewise, choosing a sample rate or bit depth higher than the source does not add detail. A 24-bit setting mainly adds headroom for recording and processing.

Bluetooth output is constrained by the Bluetooth profile and codec in use, so Default Format options may be limited or fixed. Many headsets also appear as two separate devices. When the microphone is active in a call, they switch to a hands-free mode with noticeably lower audio quality.

The output format does not affect background noise picked up by a microphone. Noise depends on mic placement, the input level, and any noise suppression your call app or driver provides. Some drivers also apply their own enhancements or effects on a separate tab. Their availability and behavior vary by manufacturer, so check what your device actually offers.

Settings apply to each device separately. Some apps can choose their own output device or format. Windows 11 arranges sound settings differently, so treat the menu locations above as Windows 10 guidance and confirm them on your build.