Before any mixing can be done, we need to have a list of what inputs as well as outputs that will be needed. We need to plan where everything will be located on the stage, as well as where we will need to place our speakers. This can be done using a simply stage plot. This can be hand drawn or you can use a free online tool similar to the one found at https://tecrider.com/ , or a paid version like https://www.stageplot.com/.
Once we know where everything is going to be located on stage, we need to run our cables for mics, keyboards, stage monitors and DI boxes, being careful that we avoid any trip hazards by routing them out of the performers way, or taping them down. This also goes for any electrical lines/extension cords used for amps, cooling fans or lighting.
Now we can hookup our mics, instruments, DI boxes, stage monitors, pre-amps, amps, crossovers, eqs and front of house speakers, (FOH). There is a process to turning on, as well as turning off the sound system, to avoid that dreaded “POP” which could also cause damage to your equipment.
This process will very depending on what equipment you are using in your signal chain. As a rule of thumb, you would simply start at the beginning of the signal path, your mixer, and end with the last item in this chain, your speakers. You simply reverse this order when shutting everything down.
When setting up your stage monitors, you want them pointing up towards the performer and directly behind their mic if possible. You want to avoid having them pointed directly at reflective surfaces such as side walls, or towards any open mics on stage. This will help reduce feedback issues along with allowing each performer to hear what they need to, in order to do their job. By having the mics and stage monitors positioned properly, it will make the mixing process much easier.
Now we are ready to power up the mixer, but before we do, we need to insure that the master fader is pulled all the way down. This is done to make sure we don’t get any unexpected loud noises that could possibly damage our speakers. The X/M 32 mixers have a feature called “Safe Main Levels”, that when turned on, the master fader will automatically be set to the lowest setting whenever the mixer is turned on.
At this point we would turn on the stage boxes, pre-amps, amps, crossovers and anything else in the signal path that is powered, and then finally the speakers. If you are using powered speakers, most of them have built in crossovers and you would then simply turn on the mixer, stage box and then your speakers. It is impossible to list all the combinations that can be placed in the signal path. If they are powered, simply follow the signal from the mixer to the speaker and turn them on in that order.
I would like to say a brief statement about two of the most important things when it comes to mixing live music, or even studio recording for that matter, before the mixer is turned on. Microphone Choice and Microphone Placement. You can have the most expensive mixer on the market in 2022, but if you get these two things wrong, you will be fighting a uphill battle before you even do your sound check.
Most microphones used on stage are dynamic, with a cardioid pattern. The term “Cardioid” refers to the shape of the human heart. The cardioid pattern picks up the sound directly in front of the mic, while rejecting unwanted sound from the sides and has a very narrow pickup pattern at the rear.
Small diaphragm condenser microphones are normally used for the choirs, inside of acoustic pianos, violins, overheads for the drums, house mics for live streaming or sending the signal to cry rooms and headsets. Medium to large condenser microphones may be better for certain sounds coming from guitar amps or background singers positioned away from other loud sources.
If you think you will be having feedback issues, you may want to consider using super cardioid mics for your vocals, but you need to be aware that they have a narrower pickup pattern in the front, and will require proper mic technique from a singer that has been trained on their proper use.
Take your time and experiment with the mics at different locations, especially for the drums. Depending on the size of the room, you may be able to just mic the kick and use two overheads. If the room is really small, you may need the mics for your live stream, while having them bypass your PA system. There is no set process for this other then to experiment to see what mic placement gives you the desired sound you are looking for.
Now that we have the mics roughly where we want them and all our instruments and DI Boxes are turned on, it’s time to start setting our input levels coming into the mixer. We are looking for the “Nominal” level for our inputs and we have basically two different ways of doing this. The first method will require the channel faders moved all the way down, or at the infinity position.
Since all microphones and instruments will have different voltage outputs, we need to use gain to bring them up to the nominal level of the mixer. The nominal level is the most efficient level for the mixer to operate at, without causing distortion or added noise. For the X/M32 mixers, that is going to be around a -18dBFS for most inputs.
We will defer from the above statement when we start working with percussion instrument inputs due to transients. The mixers nominal lever will always be higher the the level of the other inputs.
When setting the gain inputs, we want to make sure that we keep an eye on the Solo/MC meter and have the monitor source set to L/R PFL, (Pre Fader Listen). This will give us a more precise reading of the input level via the Solo/MC meter, as well as hearing it when we have our headphones on, with the channel soloed and the fader moved down to infinity or muted.
Start by having the singer or musician start singing or playing like they will be during the live set. Slowly increase the gain till you reach the nominal level of the mixer, which in our case using the X/M32 mixer will be around 0 dBFS, (dBFS, or decibels relative to Full Scale, is used to measure digital audio signal levels. dBFS is another dimensionless quantity, because it is just a number and cannot be converted to another unit).
If you go past 0 dBFS, (-18dBs on the meters), when setting your input gain, you will find it is going to be harder to balance your mix as we get further into the mixing process by adding in more channels, channel strip processing and effects. If you have ever used a Digital Audio Workstation, (DAW) like Reaper, you may have noticed that depending on the number of tracks you have open, your master bus could start clipping while all your tracks stay below clipping.
There is a mathematical formula that basically states that for every two inputs you have when your inputs are set to nominal, you will add 3dBs into the signal chain. Your stereo output is the SUM of all your audio channels. In other words, two channels outputting the same value will double the SUM at the master bus. By keeping proper input levels you will have plenty of headroom for mixing, channel strip processing, buses, DCAs and adding effects.
So what is that magic number for the X/M32 Digital Mixers? There is a very easy way to check. If you go to your “Monitor Tab” and then to “Oscillator”, choose “Main L+R” as your “Destination”, then select “Sine Wave” as the “Oscillator Type”. Raise the “Oscillator Level” to a “-18dB”, then look at your main meters. They should be one LED light into the orange or close to it.
The input level is so important and it is truly the starting point for consistent live mixing. We need to realize that this input level can change due to eq’ing, compression, DCAs, buses as well as added effects. It is vital to start with the proper gain staging throughout the signal path, from the inputs to the speakers.
In part two of this article, we will discuss the procedure for setting our input gain using the “Mixing to Unity” Method, as well as adding channel strip processing, using DCAs and setting up monitor mixes for stage wedges and In Ear Monitors, (IEMs) and setting the gains on your powered speakers. As I mentioned before, I am not going to say that this method if mixing is incorrect, but I will say that if you are new to mixing, you may want to get a little time under your belt with the X/M32 mixers before you try this method for live mixing. YBIC, Dana Tucker.