Each aux send on your mixer enables you to create a unique mix that is different from the main mix. This explains why aux sends are primarily used for monitor mixes. So, if you have four sets of aux sends, you can have four unique monitor mixes in addition to your main mix.
So, let’s go through how to use aux sends for monitor mixes step by step.
On the back of your mixer, there is a section labeled ‘Aux Sends’. This is the output signal for each aux send on your mixer. You need to use a balanced cable to connect the aux send to the monitor.
You are most likely using a stage snake to get the signal from your mixer all the way to the stage. Rest assured that every cable in the stage snake is balanced. For all other cables used, make sure they have either an XLR connecter (like those used on a microphone) or a TRS connector, as both of these indicate a balanced cable.
Keep in mind, it is easy to confuse a TRS connector with a regular instrument cable connector. They are both 1/4” connectors, but if you look close, the TRS connector has two rings whereas a regular instrument cable has only one. An instrument cable is unbalanced, and if you use it instead of a balanced cable, you will get all kinds of unwanted noise.
Now that you have the right cables, it is time connect your monitors. If you are using passive speakers, the aux send will connect to the amp that is powering the speaker. If using powered speakers, the aux send will connect directly to the speaker. If using in-ears, the aux send will connect to your headphone amp.
Once everything is connected, you are ready to head back to your soundboard and create the mix for your aux send. Towards the right of the sound board, there is a section labeled ‘aux sends’ or ‘aux masters’. These knobs control the overall output of each aux send. I recommend setting these to 0 (or 12 o'clock) to start things off. Now go through each channel to create the desired mix.
Once you have a mix you are happy with, make sure you are sending a strong signal to your monitors. To do this, head back over to the section on your soundboard that controls the overall output of the aux send and engage the button labeled ‘solo’ or ‘AFL’. This will activate the level meter on your mixer to show you what type of signal is flowing through the aux send. Much like setting the gain, you want this signal to be consistently around 0dB. Use your aux send master volume knob to achieve this.
Keep in mind that this is something you should check on a regular basis. As you make adjustments to the monitor mix, the overall output will change. If you forget to check on the output level of the aux send, you may be sending a weak signal or one that is peaking out and distorting.
Aux sends are normally pre-fader by default. However, most mixers have a PRE button which allows you to chose whether the fader at the bottom of the mixer should affect the volume of the aux sends. PRE is actually short for ‘pre-fader’. So, If PRE is active, the fader at the bottom of the mixer will not affect the aux sends. If PRE is inactive, that means the aux send is post-fader and the fader will not only adjust your main mix, but the aux sends as well.
In most cases, PRE should be active so that your fader does not affect the aux sends – especially when used for monitor mixes. Most likely, the only time you do not want to use the PRE option is when connecting a device that plays pre-service music. Otherwise, when you fade out the music, it will still be be playing through the monitors.
Unless your soundboard allows you to choose (which most do not), aux sends are post EQ. So, when adjusting the equalizer on your mixer, this will affect not only the main mix, but the aux sends as well. For example, if you are using your aux send for a monitor mix and you cut the lows out of a vocal, the lows will be cut in the mains as well as the monitor.
Drop them in the comments below.