In case you want to buy an audio mixer, there are some basic notions that you need to know in detail and to master thoroughly in order to be able to use this equipment to its full capacity, and this guide can be of real use to you. .
Although at first glance an audio mixer may seem very difficult to use, with many buttons, if you start to study them carefully you will see that many are repetitive and it is not impossible to learn to manage the equipment. To help you, I present in this article some more important notions to deepen, in order to successfully succeed in your quest to learn to work on an audio mixer.
The role of a mixer is to take the signal from different sources and send it to outputs. It generally has several channels that have the same behavior, so if you know how to use one, you will be able to use them all.
Number of inputs and outputs
As the main feature of a mixer is the number of inputs and outputs it has, and the number of channels that can be between 4 and tens depending on the model. For example, it can be a mixer with 8 inputs and 2 outputs, ie you can take the signal from 8 different sources and after processing and combining it you can send it to 2 outputs.
A channel is composed of a band of potentiometers and has several control buttons with which it processes the signal and sends it to the outputs. The input can be in several forms: XLR – for microphone, low impedance; jack – for power signals; stereo. On a 16-input mixer, for example, you can have 8 XLR microphone inputs and 8 jack inputs.
Its role is to bring the input signal to the same level, raising the small signal (of the microphone) and bypassing the strong signal (from the jack line). The low-cut and high-cut filters have the role of cutting the very low and very high frequencies, respectively, in order to diminish the background noise.
They are very important, these having the role of announcing in case the input signal is too big and exceeds the power of the preamplifier, in this case it must be diminished: it can be a simple LED or a bicolor LED that is green at the signal input and turns red when it exceeds the level.
You will use it when you want to mix stereo, it is in the form of a potentiometer and allows you to transmit the signal in the stereo field, having a wide range from total to left to total to the right.
It is very helpful when you need to listen to only one channel, to check the accuracy of the signal, which has the role of silencing the other channels that are not of interest at that time.
It is useful when you have several channels that you do not use, being good to put them in the mute position until you need them.
P ll be round or linear and allows you to adjust the volume in relation to the other channel they use.
They have only two simpler outputs (buses) with the help of which the signal is transmitted to the speakers, the more efficient models being equipped with auxiliary outputs useful especially to be able to monitor the stage in case of a concert.
For example, in order not to enter the microphone, the soloists are placed behind the speakers, and have control monitors to be heard. For them you can make a special mix, with the voice and melodic instruments louder, the rhythm section slower, using the auxiliary outputs.
The auxiliary outputs are usually equipped with switches with pre / post Fader, in the pre position they are not influenced by the movement of the Fader button, the volume remaining constant, in the post position they are directly influenced by the movement of the Fader button.
In addition to the channels, an audio mixer also has a master section that includes: master output – which allows control over the output completely; send / auxiliary master – which allows you to easily control the volume of all auxiliary outputs in case the device is equipped with them; output measurement – each device is equipped with a general display, and in some more efficient models there is a display on each channel, consisting of differently colored LEDs on certain ranges that allow you to quickly view the volume level (green – normal, yellow – close to overload, red – overload), distortion may occur during overload; headphone output – to be able to listen to certain songs independently of the overall volume in the headphones.
For a concert it is advisable to use a mono mixer so that everyone in the audience can hear the same signal, with a stereo device only those in the middle will hear properly. In case you have a stereo mixer you can use it on the mono by positioning all the Pan buttons at 12 o'clock.
It is very important to have a comfortable signal, not too loud so as not to create distortion, not too slow to be heard. On an audio mixer you have three sections with which you can adjust the volume, namely:
The first is the gain of the preamplifier that must be set as high as possible, up to the limit of distortion, if the LED in the indicator rarely lights up you can leave it at that level, but if it starts flashing more often, it must be set below.
The master output is the second control over the volume, and must be set to 0dB, when it is with positive values it indicates the application of the first control, namely the gain, when it has negative values it means that the signal is attenuated. When you start a mix it is good to set the master output to -3dB.
The last setting is made of Faders and must be set so that the peak is also at -3dB, and in case you need a stronger volume you can bring it to 0dB or a little higher. If you still feel the need for more volume, raise the level to the active speakers or the amplifier.