Live sound mixing

Live sound mixing is the blending of multiple sound sources by an audio engineer using a mixing console or software. Sounds that are mixed include those from instruments and voices which are picked up by microphones (for drum kit, lead vocals and acoustic instruments like piano or saxophone and pickups for instruments such as electric bass) and pre-recorded material, such as songs on CD or a digital audio player. Individual sources are typically equalised to adjust the bass and treble response and routed to effect processors to ultimately be amplified and reproduced via a loudspeaker system. The live sound engineer listens and balances the various audio sources in a way that best suits the needs of the event. Audio equipment is usually connected together in a sequence known as the signal chain. In live sound situations, this consists of input transducers like microphones, pickups, and DI boxes. These devices are connected, often via multicore cable, to individual channels of a mixing console. Each channel on a mixing console typically has a vertical "channel strip", which is a column of knobs and buttons which are used to adjust the level and the bass, middle register and treble of the signal. The audio console also typically allows the engineer to add effects units to each channel (addition of reverb, etc.) before they are electrically summed (blended together). A live audio sound mixer basically mixes a bunch of different signals together and then sends that blended signal to outputs (speakers). EQ mixing involved adjusting each sound source's equalization (EQ) settings to achieve a desired sound. This involves adjusting the frequency, amplitude, and resonance of each sound source. EQ can be used to create clarity and depth to the mix, as well as to customize the sound of each instrument or voice. Audio signal processing may be applied to (inserted on) individual inputs, groups of inputs, or the entire output mix, using processors that are internal to the mixer or external (outboard effects, which are often mounted in 19" racks).