Sweet Headache

Turntables with a bit of visual digital magic

Recently, I was invited to take part in a user test at the university where I studied. I didn’t really know what to expect, but according to the invitation, they specifically wanted DJs for the test. On my way to the test, I saw this more or less as a favor to the institution that I got an important part of my education from – on my way back, I felt I had seen a part of the future of DJing.

I was greeted by Justus Lauten who was working on a system called DiskPlay for his bachelor thesis in computer science. He told me that this was a system for DJs and that he was doing a user test to find out how well it worked and what he could improve.

He asked me to just step up to a pair of turntables and start mixing a bit. What I saw at first was a typical digital vinyl system (DVS). These are well-established DJ systems that use special vinyl records to control playback of MP3 files on a computer. Those systems have become quite popular among DJs in the last couple of years as they combine the advantages of real vinyl records with those of digital DJ interfaces.

However, the system that I got to use was not just a standard DVS: A projector was added to the setup, and it was projecting something right on the vinyl disc itself.

It turned out that the projector did not just project decorative images on the disc. The white vinyl disc was now showing information about the track including beginning and end of track, current play position and cue points. Especially the projected cue points are something that I found very useful: One common criticism towards digital vinyl systems is that you cannot see the track on the disc itself as you are always using the same control disc. With real vinyl records, experienced DJs can see the various parts of the track by looking at the surface of the disc – and this is something they miss with DVS.

One way to overcome this disadvantage is to use cue points: Those are time points in a track that are marked within the software. DJs typically use these cue points to mark important parts in the track such as the end of the intro, breaks or the outro. This works, but you always have to look at the computer screen to see those instead of keeping your eye on the turntable and the mixer.

DiskPlay compensates this by showing the cue points and more on the disc itself. Here is an example:

The green area of the track shows me what has already been played, the blue part is the rest of the track and the thin line marks a cue point. The red part is an indicator for when the track ends – you wouldn’t want to be surprised by a track that ends before you have the next one ready.

After playing around with this system for a while, I got used to it pretty quickly. The colors showed to be useful extra information, and I was much faster in finding cue points than by looking at the screen. I also noticed that this felt much more natural and easier to use than a normal DJ system.

As Justus was looking for ways to improve this system, I did find a few things to improve: Automatic display of the waveform might be useful to see more information. A more attractive visualization could be great to make this an explicit part of a DJ performance. And of course, the setup needs to be much more compact for this to be actually usable in a club.

This system was just a research prototype that was used to figure out if projecting information onto a disc is useful at all. However, I think this is a great idea overall and with some refinement, this might actually be a great addition to current commercial DVSs.