Q4™ Using & Applications

The Radial Q4 is a straight-forward semi-parametric EQ designed for 500 series power racks. It features top and bottom shelving with two semi-parametric mid bands. Those who are familiar with parametric EQs will find it comfortable and effortless to use. The following page outlines the basic functionality. For those who are interested in more detail, we invite you to download the full manual by clicking on the icon at left.


The Q4 is a semi-parametric EQ. What this means is that it tries to balance functionality and speed with a greater degree of control where it matters most. To this end, there are four frequency bands at play. The low and high bands are fixed for easy manipulation while the mid band is divided into lower and upper ranges which in turn can be controlled by sweeping the frequency and then either increasing or decreasing the effect using the associated amplitude control. The width or Q of the frequency range can be narrow or wide depending on the desired effect. This proven format has been used by console manufacturers for years as it has been found to provide plenty of range while only requiring a limited set of controls. This recipe is well suited for the limited space available on a 500 series module.

Plugging In & making connections

As with all 500 series modules, make sure you power down before plugging the Q4 into your power rack. This eliminates the possibility of turn-on sparks that could damage other equipment and may shorten the life of the card-edge connector. Make sure the module is properly seated and then secure it in place using the supplied Phillips screws. Depressing the EQ-IN button near the bottom of the face plate will activate an LED and let you know that the Q4 is powered.

The Q4 is designed to process balanced line level signals using the XLR connector on your 500 series power rack. If you have a Radial Workhorse, you can also go in and out of the Q4 using the Omniport ¼" TRS connection. This lets you connect to and from your mixer's insert point using a single TRS cable. Simply turn on the EQ circuit by pushing the EQ IN button on. The LED will illuminate.

Adjusting the EQ

The Q4 has 4 EQ bands. These have been carefully designed to provide a wide range of effects that will enhance an instrument, voice or program track. Using the Q4 is merely a matter of turning knobs and listening to the effect. Start with all of the knobs in the 12 o'clock position and the Q set wide. Experiment. There are no rules when it comes to using an equalizer... simply use your ears.

Control Type



High Shelving 10kHz
Hi-Mid Parametric 1kHz ~ 8kHz
Lo-Mid Parametric 300Hz ~ 2.4kHz
Low Shelving 100Hz