A sound card mixer is a software application that controls sound levels on a computer. It is also the name for the part of the sound card hardware chipset that controls the volume levels on a computer sound card. Usually, a sound card mixer refers to a type of volume control that gives the user individual control of the sound volume level of several programs or audio input and output channels. A sound mixer can often be accessed from an operating system toolbar tray or in the sound card settings or preferences panel.
On older sound cards, a sound card mixer is usually the interface for control over the levels of the speakers and audio channels available in the sound card. Some newer sound cards offer control over the sound levels in individual programs, allowing the user to give different audio programs, like browsers and video players, different volume levels from within the sound card. This feature can be helpful for programs with no built-in volume control.
Volume control in a sound card mixer is often expressed with sliding controllers that a user moves up and down to boost or reduce sound in that channel. Common channel options that might appear on a sound card mixer include left, right, front, and rear channel controls. Advanced sound card mixer programs may include individual program volume controls for each running application, including browsers, video programs, music players, and other software.
When sound problems happen on a computer, checking the settings for the mixer on the computer sound card is a good early troubleshooting step. If sound is not playing correctly from a certain channel or program, it could be because a track or channel is muted or turned down on the software mixer. The mixer can also be used to boost recorded sound or balance sound levels when using sound from multiple programs.
The computer sound card is the hardware that allows a computer to record and play sound. While most sound cards exist as internal hardware in a computer, some sound cards connect to a computer using a universal serial bus (USB) or firewire plug. Sound cards can be simple or advanced. Some sound cards handle only basic sound functions like two-speaker audio and single-channel audio inputs for recording. Professionals use high-end sound cards designed especially for recording multiple channels. Advanced, high-end professional sound cards tend to have more elaborate sound card mixer applications to give a skillful sound engineer more audio control.