This is the next series of guides on how to record and produce tracks for those who are new to working with audio.
Specifically, this series will walk you through recording and mixing a track on Logic Pro x, as it’s the most commonly used audio workstation. There will be weekly additions to this blog, each concentrating on a new part of the process.
- Frequency bands
One of the fundamentals of sound is frequency. Frequency links directly to a pitch of a soundwave. The lower the frequency is, the lower the pitch, and the same with high frequencies and high pitches. This means that the changing of the level of frequencies of audio can change the way the audio sounds, known as tone.
This is very important to know when mixing together audio. Playing together two pieces of audio with similar tones can cause particular frequencies to build up in volume and be heard very present in the mix. This can cause the whole track to sound muddy, harsh or just wrong. Therefore it’s important to know and remember which frequencies are particularly prominent in different instrument recordings.
Here are a few common examples:-
- Bass guitars 50Hz-250Hz
- Bass drums 20Hz-200Hz
- Cymbals 2kHz-20kHz
- Snare drum 100Hz-1kHz
- Vocals and Guitars will clash together in the range of 500Hz-4kHz
The process of equalisation is the attempt to balance the spread of frequencies across a mix. This can be done using an equaliser or filters.
The most straightforward of filters are high and low pass. The highpass filter will block low frequencies below a threshold and allow high frequencies to pass. The lowpass filter will do the opposite and allow low frequencies through.
You can use both filters to cut off unnecessary audio information that the human can’t hear, below 20Hz and above 20kHz. High pass filters are especially useful for cutting out rumble or hum on recorded audio and guitar amps.
There are also two main types of equalizers; graphic and parametric. A graphic EQ is the more simple of the two. Most will have a select amount of preset frequency bands that you can either cut or boost.
These bands or frequencies are fixed and can’t be changed. In a parametric EQ, you have the ability to choose which frequencies you’d like to boost or cut. Graphic equalizers are more commonly found as hardware whereas parametric are more often found as software.
The standard EQ in Logic is this parametric equalizer. You can click the Analyzer at the bottom right and this will display a live feed of the gain of each frequency as the audio is playing.
Using the analyzer function you can see which frequencies are particularly prominent in the audio.
Generally, you’d want to decrease the level of any frequencies that are far too prominent or aren’t wanted, such as hum or rumble. You can then also try to equalise the frequency though it’s best to use your ears to try to balance the frequencies across the whole mix and not just one channel, as this will have the best-sounding results.
You can also use an analyzer/multimeter device across your output channel which will allow you to see where there are frequency build-ups, and you can then choose an audio track which is prominently within that frequency range and reduce the frequency there.
There are a few other parts of the EQ that are important to know. One of these is the ‘Q’. This parameter how wide the range of frequencies that are affected by the change in gain. A Smaller Q will mean a smaller range of frequencies will be boosted or reduced and visa versa.
The other is what the different shapes across the top of the EQ are.
The first symbol in red is a filter. Specifically in this case it’s a highpass filter. The bottom band of the EQ on Logic is set to be a high pass filter by default, also the top band is set as a lowpass filter by default. The next symbol in orange is known as a shelf filter. A shelf will boost or lower the frequency on whichever side the two lines face, in this example to the left. The final symbol is the most common and it will simply boost or reduce a selected band of frequencies.
Being able to use an equalizer to create high level results is something that takes a large amount of practise. You’ll need to use your ears to be able to EQ audio to sound good, rather than relying too much on what things look like on screen.
You’ll also need to take into account that all pieces of hardware that the audio signal will pass through both on it’s way into the DAW and out of the DAW will have a colouring effect on the frequencies. What this means is that the frequencies of the signal will be changed slightly by the device it’s passing through. You can often find out the colouring properties that your devices have and using them you can control your frequency balance much more.
You should now have be able to start equalising and balancing your audio.