The mixing console or "mixer" is a central component of most sound systems. In fact, the mixer used will have a large influence on the operability and efficiency of the entire system. One of the first decisions that will have to be made when designing a new sound system is whether a digital or analog mixer will be used.

Both digital and analog mixers are available in console configurations that are normally used on table top or stand, and rack-mount configurations with vertical control panels designed for installation in standard equipment racks. The choice will depend on the application, the type of operability required, and the space available.

Choosing the right processing capabilities for a commercial sound system is essential in achieving the desired clarity, naturalness, and flexibility. Digital audio devices offer a wide range of processing capabilities that can be extremely useful in such applications. Let's start by taking a look at the basic types of processing that are available.

Once the physical components of a sound system have been properly installed, then it's time to begin the process of "tuning" the system for optimum matching with the acoustic characteristics of the space as well as the speakers used. If the system is not properly tuned, the full potential of all the carefully selected components will not be realized.

In the next three sections we'll take a look at feedback, from what causes it to how it can be controlled. Although feedback control is only a small part of the tuning process, we hope this will give you a feel for the kind of detail that overall room tuning entails.

Feedback occurs at a specific frequency that is emphasized more than others. It stands to reason that if you can locate that frequency and reduce it's level, you can stop the feedback. Equalizers are ideal for this purpose, so in this section we'll look at how graphic equalizers are used for feedback control.

In the hands of sound professionals, equalizers can be effective tools for combating feedback. But in facilities where experienced personnel are not always available it may be wiser to employ other means. The reasons and solutions are discussed below.

One of the many benefits provided by digital sound systems is the ability to include convenient automated mix functions. Such functions can significantly reduce the burden on staff for basic BGM distribution and events such as speeches or lectures, eliminating the need for a sound professional to be available full time.

If you're planning on going digital, it is definitely worthwhile looking at the capabilities offered by external controllers. External controllers can not only provide convenient remote control of the sound system, but custom interfaces that are tailored to the system and easy for inexperienced operators to use as well. External controllers can increase the usability and value of just about any installed system.