Drive Rack

The drive rack is a component that has all the system processors that connect between the mixing desks output and the power amp inputs. Since everything passes through them it is important to have a decent quality rack instead of a lower range one. By system processors I mean dynamics processors, EQs and time alignment delays.

Dynamics processors are basically you compressors and limiters. A compressor are used to control the overall level of a signal, stopping it from getting to loud or too quiet without you constantly monitoring it yourself and keeps the sound under control. Too much compression kills the dynamics in a song. Limiters are a much more extreme form of compression with rations of 10:1 up to infinity:1 whereas compressors only go from 1:1 to 10:1.

Equalizers are an essential item in any rack or studio. They allow the user to cut and boost frequencies to get the particular sound that they want. In the live scenario the drive rack EQ is used to treat a room. Each room in a live environment can have its own affect on sounds and how they react based on how they are made up. The engineer would put mics in the room then push the gain up as far as it could go on them till feedback starts happening. The gain would then be pulled back till just before the feedback happens and then use a 31-band equalizer to adjust the frequencies to prevent standing waves.

Time alignment delays are delays that keep all frequency related components in phase when they reach the audience. The delay times are normally extremely small for example being a fraction of a millisecond. When the proper time alignments are in effect, the result is a full and powerful sound that spreads throughout the whole room wherever the gig is at.