Master the Art of Mixing
So you want to master the art of mixing songs? Well so do I! Ha Ha! And I've been mixing music now for over ten years and I'm still learning something new everyday.
So how can I help you, you're probably thinking?
We'll I can show you the basics. Show you what tools you will be using. Show you how to use them and teach you what it is you're trying to do during the mixing process. Then the rest is up to you. Mixing songs is an individual thing and everyone will do it differently. You need to find your own way.
In this tutorial the first thing you will learn about is the very basics of mixing songs. This will give you a better idea of the BIG picture and then I will take you through the more detailed processes.
The Basics Of Mixing Songs
A mixer, audio board, mixing board or mixing desk is an interface that lets you manipulate different audio-channels by tweaking their
- positions and
- balance or
- by adding effects.
You can control each individual audio channel by panning them across the stereo, or by adjusting their equalizers, or by muting or damping or boosting them, or do any of the other thousand things possible by using a mixer.
All these different audio-channels are then combined into one seamless output.
At this point you are probably wondering why do we even need to do all of these things.
The reason is that audio inputs are picked up by mics which are basically transducers.
These mics produce very low output signals which need to be amplified to line-level for manipulation. At line-level signals can be easily manipulated by devices such as mixing consoles.
Mixers take all the various input signals like vocals, and instruments and blend them to produce an output signal. This output signal is sent to the amplifier which amplifies them to a strength which can actuate loudspeakers.
The loudspeakers convert the amplified signal into sound and play it back to you. Now consider how many different instruments and vocals come together to create a score and you will understand why a mixer is essential.
The main tool that you'll be using during the mixing process is the mixer.
To the right is a picture of the Pro Tools mixer window. This is what a typical software mixer looks like and if you can use one you can use any of them.
A mixer allows you to mix your tracks together so that they all fit together in the mix without fighting eachother.
Below you will find out more about each of the different mixers.
Different Types Of Mixers
There are 3 different types of mixers which you will encounter. Although they all do the same thing they do differ from each other. Click the images above to find out more.
Understanding How A Mixer Works
The Input section of a mixer is where you plug-in the mics, instruments or even a CD player from which you plan to generate and send audio signals into the mixer. Physically the input connectors are either;
- XLR type for Mics
- 6.5mm Jacks for instruments
- RCA type for CD players
Below is a picture of what each of the inputs look like.
Electrically, input connections can be classified as;
- Mic-level, which is the weak output from the mic
- Line-level, which is the amplified signal from the preamps of the mic
or as balanced or unbalanced;
- Balanced Connections being designated as Hi-Z
- Unbalanced Connections being designated as Low-Z (where Z stands for impedance)
Balanced signals are always used in professional set-ups since they eliminate interference between wires, which is the electromagnetic field set up around current carrying wires.
However unbalanced connections will work fine for most musicians as there isn’t that much length of cable between the various equipment to make interference a significant factor.
Not all microphones produce the same output. Some may have a weaker signal than the other. Or if you are recording a duet, one singer sings softly as compared to the other. These variations in output from the mics have to be adjusted at the input to the mixer.
A strong, consistent and balanced input is essential for getting good sound throughout the system. This balancing is done by the “Trim Control” or “Gain Control”.
The trim control reduces the decibel level of the input and the gain control adds to the decibel level of the input. So by using either of the two you can increase or decrease the strength of your input channels.
These adjustments are usually only done once before the recording starts. Most pre-amps produce distortion when they operate at “Unity Gain” i.e. there is no trim or gain in the input. Therefore attenuator pads which boost the input signals by 10 or 20 db are installed between the input and the pre-amps.
The Channel Strip is divided into the following sections:
- Mic Pre-amps
- Dynamic Processing
- Input Faders
Let us take a quick look at some of the common functionality found in the channel strip.
The equalizer is a functionality that allows you to modify the tone of the sound. This can be done by boosting different frequencies within the channel and thus boosting its bass, treble etc.
Most mixers will have a rotary equalizer which can boost or cut “highs” and “lows” by frequency selection with a potentiometer. Professional mixing desks use parametric equalizers which have bandwidth control as well as “high-pass” and “low-pass” filter.
The panning slider is a functionality that allows you to control the stereo pan of the audio channels. A knob is provided which can be turned from left to right or vice versa depending on which direction you want the sound to come from. Panning is also utilized to reduce or increase the stereo spread of a channel.
The Mute functionality mutes a specific channel in the score. If you select the Solo functionality for a channel, all other channels will automatically be muted. The mixer is said to be in “Solo Mode” if a channel is solo-ed thus cancelling out any other mutes on other tracks.
There are various meters on the mixing desk which are used to monitor the level of the output from the various busses and groups. The Volume Unit meter is the simplest and most popular of these. It outputs the RMS value of a channel, which is the average voltage level of the electrical signal representing the audio channel. Sustain sounds can easily over-load such meters as compared to percussion sounds, since they measure the amplitude as well as duration of peaks of the signal.
Apart from these, you have functionality such as Record Enable, which lets you specify which staves or channels you want to record. This is useful where you are doing multi-track recording as also functionality such as volume faders which are used to control the “fade-in” and “fade-out” of tracks.
Once you have your input instrument plugged into the mixer, you have to “route” its input to a “bus”. This is known as routing. The three main types of buses are:
- Auxiliary Bus - The auxiliary bus is where your audio signal goes to when you use the send function from your input channel strip. Using the channel strip contained within the bus, you can manipulate the audio signal any way you want. From here the individual signals are sent to either the sub-mix bus or the master bus. For e.g. a vocal channel can be sent directly to the master bus while a bunch of percussion channels can be sent from the auxiliary bus to the submix bus for further processing.
- Submix Bus - The submix bus is useful if you are controlling a group of similar instruments within the mixed track. This way you can separate your entire drum sounds from the main master track, divert them to a submix bus where you can mix them independently of the stringed instruments in your track (which can be mixed in another submix bus) before sending the outputs of both the submix bus to the master bus for the final mixing. This lets you manipulate groups of instruments independently of other channels in the tracks.
- Master Bus - The Master Bus is where the actual mixing of your channels happens. You can use the panning slider to manipulate the stereo width of the channel, the equalizer to modify the tonality, the volume faders or use effects like compressors. The output from the master bus goes to the speakers, so it won’t have knobs and controls for things such as solo or mute. The fader in the master bus only controls the overall volume of all the channels being mixed in it. It does not control the individual levels of the channels or their levels in relation to each other. This is the final stage of your mixing.
The output of a mixing desk consists of a number of jacks. These are as below:
- Master Out Jack
The Master Out Jack connects to the power amplifiers that boost your output to a level that will drive your speakers or loudspeakers. The master fader controls the levels of the channels that are routed from the master bus to the Master Out Jack.
- Phones Jack
As the name suggests, the Phones Jack received the signal from the headphones knob on the master console, and outputs the signal via your headphones. Normally this will carry the same signal being output in the Master Our Jack. The only difference is you can control the levels of either of the jacks independently.
- Monitors Jack
Again, the Monitors Jack carries the same signal as carried by the phones jack or the master out jack. This connection carries the signal from the master bus to your monitor speakers. An additional functionality of this jack is in the use of hardware monitoring, which is a procedure where you can directly pick up your audio input from the input interface rather than wait for the signal to pass through the mixer and the output. This is useful for live performances, DJing etc. where you want to hear yourself play with minimal latency.
Hopefully you now have an overall idea of the various components of a mixing desk and how the process works. You are now that much closer to successfully composing your own digital music.
The Process Of Mixing Songs
- Panning - Positioning your tracks left to right within the stereo field.
- Levels - Setting the volume of your tracks relative to each other so that nothing is lost in the mix.
- EQ - Adjusting the frequency of your tracks.
- Effects - Adding whatever effects you think your song needs such as reverb, delay, compression etc...
Check out my guide "How To Use A Mixing Desk" for more info on actually mixing a song.