Art and science collide! If you use any digital DJ software or DAW you have probably worked with waveforms. But what are they exactly?
We’ll start at the beginning…
Sound is a sequence of waves of pressure that travel through a compressible medium (like air and water). These pressure waves can be created from almost anything, from the vibrations of human vocal chords to the in-and-out movement of a speaker cone. There are a few different ways that sound can be visually represented, but one of the most common is the linear waveform.
As we can see from the picture above, there are several distinct parts of a waveform, but two of the most important for DJs are the amplitude and wavelength. The amplitude is basically the height of the waveform and represents how loud the sound is. The wavelength is the distance between two crests (or troughs) of the wave and represents the pitch of the sound. Longer wavelengths represent low frequencies and short wavelengths represent high frequencies.
The photo above is a representation of one single basic sinusoidal wave, but almost all sounds we hear are made up of many different waves. A complete song can be thought of as an intricate mosaic of waves, covering most of the audible spectrum (about 20 Hz to 20,000 Hz).
If you want to learn more details about the science of sound waves, you can check out the Wikipedia article on sound here.
The picture above is a waveform of a complete song. While you won’t be able to separate out the individual waveforms from this picture, you can still see a lot of information (if you know what to look for).
The spectrum in this section above is fairly narrow without any large transients (a high amplitude, short duration sound at the beginning of waveform events). This low-amplitude, consistent waveform is a representation of a medium-loud harmonic sound.
This next spectrum still has the narrow waveform in the middle, but is dotted with larger transients. These large amplitude sections are louder than the middle section and represent drum kick and snare sounds. Since low frequencies have longer wavelengths, you can actually see which of these hits are the kicks and which are the snares (given that kicks have lower pitch than snares). In the kick waveforms you can actually see most of the crests and troughs (like the first in the sequence), while wavelength of the snare waveforms is much smaller so you cannot differentiate between individual crests and troughs (like in the third hit of the sequence). If you were to zoom in to the waveform more you would be able to see more detail, but as a DJ you probably won’t be looking at waveforms at much more of smaller scale than this.
In this picture, you can see that the kick and snare hits are still present, but the space in between them has filled out more. This means that there is more sonic content, which (in our context) means that there is a drum line and harmonic line occurring simultaneously (like a verse or chorus).
The information above is really just a primer on some of the basics that you will need to know as a DJ. The more you work with waveforms and the more you read about them, the better you will understand them. Every piece of digital DJ software handles and displays waveforms in a different way, but the basics will remain the same. In Traktor, the display is fairly basic, but you do have some options to customize what yo see. The Serato waveform display is slightly more complex, separating the low, mid, and high frequencies into red, green, and blue colors. Some people find this visual separation of the frequency spectrum very useful, while others find it distracting (it’s really a matter of personal preference). In Ableton Live (which I used for the examples above), you have quite a bit of waveform detail and an in-depth adaptable grid system. You may have noticed the green squares above the waveform at certain points; these are warp markers. Live analyzes each waveform and places these ‘pins‘ in the waveform at certain points (like the downbeats) so that you can change the tempo and pitch independently.
Regardless of how you DJ, you should try to learn as much about waveforms and how to interact with them in your software of choice. You shouldn’t rely on the visuals in your software to mix, but it can be a great aid when you’re in a bind or trying something new.
If you want to learn more about DJing and gear we highly recommend you check out our online DJ School here at Spin-Academy.