Going down the rabbit hole of DJ mixing / 2023-08-13

I had a heavy case of 'Oh Shiny!' this weekend. Recently I've been viewing and listening some DJ mixes on YouTube, most of them with music from the 1980s which I appreciate a lot.

Seeing those DJs mix live in those videos made me wonder 'how do they do it'. In one or more of these mixes I really noticed that a transition seemed to have happened between one well-known song and another, but I wasn't aware of how and when the transition happened. The DJ was so good in mixing the two records together I couldn't hear the point where it happened. In seeking the video I saw that other people viewing the video had been wondering the same, there was clearly a peak in viewing time on the transitions. It was also clear from the look on the face of the DJ he was happy with what he accomplished with that transition!

In the 1980s the DJ had an audio mixer and two turntables, almost always the Technics SL1200 with pitch control and fast start/stop. Nowadays this can be done in software. From a music collection on harddisk with controls to mix 2 or 4 tracks, with effects, equalizer and speed control. The modern DJ has a laptop!

I soon found out there is open source DJ mixing software that supports Linux! Mixxx - Free DJ Mixing Software App is open source and multiplatform. And it is available as an Ubuntu package so I gave it a spin (pun intended). Only having one audio device is 'supported' but it took me some trying to find a setup where I could work 'split' with a master mix in one ear and a headphone mix in the other. So I loaded some music and tried to make it into a bit of a DJ mix. I'm not very good at it, but I enjoyed trying.

Mixxx really prefers Jack audio since it likes having a lot of audio channels. I tried installing Jack audio in linux but couldn't get it to do what I want fast. Mixxx also supports the Alsa drivers and I managed to also set it up to route the main audio to a USB audio device and the headphone audio to the internal headphone jack. But I had nothing connected to the USB audio device and I didn't want to annoy my family with the noises of trying to make a good cutover from one song to the next. Mixxx has an option 'Split' to play the master output to one ear of the headphones and the headphone output to another, this is good for practicing.

Control of all the mixing functions in Mixxx can be done with mouse and keyboard, but the good part is it also supports all kinds of hardware DJ controllers. And some of them aren't too expensive... and available on the second hand market for an even better price.