What To Look For In An iPad, iPhone Or iPod Touch DJ App

There are scores of DJ apps in the iOS app stores, and it can be difficult when faced with such a selection knowing which ones are worth your time and money and which aren’t. It’s not helped by the fact that what’s possible on the platform has improved dramatically recently, but some of the apps in there haven’t kept pace.

You only need to briefly dip into the forums of Algoriddim (the company that makes the popular djay app) to appreciate the demands being made by customers. Some are incredible! So, in 2012, what should you realistically be looking for when considering which DJ app to download to try on your iPhone, iPad or iPod touch?

Must-haves

These are features which should be present in every DJ app without question. If the app you’re considering doesn’t have these, then walk on by…

• Direct music library access – This is already well-documented, established and working in nearly every DJ app available, therefore it should be expected. If the app doesn’t provide it, forcing you to go through some convoluted process to get your music into it, then the chances are that it is really old app and you won’t be seeing an update any time soon!
• Decent output options – Specifically, the app must offer some form of pre-cueing. The most common solution to this (given the single stereo output situation on iOS) is to use a splitter cable such as the AOIDJ or Griffin cables. If an app relies solely on the use of its “Sync” button functionality or visual alignment of waveforms to replace pre-cueing, then (at least from my experience) it probably wont return reliable results. (Note that some DJ apps also offer single deck modes, in which case you’ll either use two iOS devices with a mixer, or just use one as a “third deck”, and so pre-cueing is unnecessary)
• A simple interface – For a DJ to use any interface (regardless of whether it’s on iOS) in a live environment, it must be clean (clutter-free) and intuitive. You should be able to access all the main and regularly used features quickly and efficiently. There are some dreadfully designed DJ apps out there, and on a small screen, it becomes even more critical

  

• Good stability and performance – Some DJ apps are rock-solid; you can throw everything at them. You can have a track looped, key-locked in reverse with FX applied while loading another track and the experience is seamless. On others the simple process of loading a second track can cause audio glitching, drop-outs and even crash the app completely. Before buying an app, remember to check which iOS version is supported, and which devices are compatible with it
• Quality audio playback – Surprisingly, the audio playback quality between apps differs. This is because while the source track from the music library is the same, the method used to alter tempo and process the audio can be different. A good test here is to load a track in your DJ app of choice, select the largest pitch increment setting (100% is occasionally available) and then slow the track right down from zero through to the 80%-90% range. Ideally the audio at these speeds should sound smooth, but unfortunately this is not always the case. In some DJ apps you’ll find the audio gets choppy and glitchy. If you want to use the app with a USB Midi controller or are trying to scratch (yes, even on a flat touchscreen some people do!) then this will be critical to you and even more noticeable if playing out at high volumes
• File format support – If you can play a file format in the music library then you should expect to be able to use it in your DJ app. Similar to music library access, this hasn’t always been the case

Crowdpleasers

These are the features which raise a DJ app above simple audio playback and mixing between two tracks. They are mostly for serious DJs; casual users are less likely to be interested in the number of cue points an app provides or the quality of track analysis. If you’re considering purchasing an app which promises to be a “pro-level DJ app” but it doesn’t have any of these features, then it probably won’t live up to the hype.

• • Cue points – This screenshot shows an impressive eight cue points available in the DJ Player and Red Bull BPM DJ apps on the iPad (there are a couple fewer if you’re on an iPhone/iPod Touch). Each cue point can be set up as a loop and can be finely tuned to ensure accuracy. The more cue points available, the more creative you can get – even down to using the cue points as you would pads on an MPC sampler to break down a beat. The crucial detail of cue points is that they get stored against the track, so you don’t need to reset them next time the track is loaded. Ideally you need to be able to fine tune them and adjust start and end points manually too
  • Looping – Functionality around looping differs greatly among DJ apps. At the simplest you get the track looped during playback for a set number of beats. At the most complex, you get the ability to set and store start and end loop points and maybe allow the track to continue from where it should be if looping had not taken place

    

  • Effects – As with looping, the range and quality of effects varies between apps. For me, FX functionality works best on iOS when you are presented with an X-Y axis (as with a KaossPad) to change the parameters of an effect. If you’re faced with rotary dials as a control of an effect then it is much more difficult to work with quickly. djay has some neat FX combination buttons which are useful
  • Sophisticated track analysis – Quality of BPM detection, application of a beatgrid and calculation of the waveform for display can all vary. If any of these are less than excellent, then any loop functionality is potentially going to sound awkward and you would need to avoid using the sync button, for instance
  • In-app recording – A great way to capture your iOS DJ efforts. Just make sure you have enough space available before you start recording!
  • Social networking links – Integration with the likes of Twitter and Facebook has become easier in more recent versions of iOS and therefore more apps are using it as a method of spreading the word. Several DJ apps offer the chance to automatically post details of tracks played as you’re playing them. It’s a complete about-turn from the days of steaming labels off records so that other DJs or clubbers couldn’t identify what was playing!

“Just For Experts”

These are for the more adventurous user of DJ apps. If you’re considering using an app professionally, in a live environment, then most of these will probably be on your wishlist.

• Keylock – There are two approaches: “time domain” (lower quality, less power needed) and “frequency domain” (higher quality, used in Traktor and Serato, complex and typically more power required). djay uses the frequency domain method of zplane’s élastique plugin code – but only on iPad 2 and upwards. DJ Player and Red Bull BPM DJ have developed their own frequency domain keylock code, which runs on older, single-core iOS devices (except iPhone 3GS)
• Sampling and sample pads – Mixr is one of the more recent apps to offer the use of sample pads to drop one-hit sounds into the mix
• USB Midi support – With the number of manufacturers developing USB Midi controllers for use with iOS devices increasing, the demand for this feature is likely to rise too. djay is currently leading the way with support for several different controllers (Vestax Spin, iOn iDJ2Go and Numark’s iDJ Live, iDJ Pro and Mixdeck Quad), however more apps are starting to follow suit
• Data backup – Imagine you’ve spent some considerable time going through your playlist and setting cue points in the app. When you’ve loaded a track for the first time, its waveform, BPM and possibly beatgrid have been calculated and stored. On a laptop you can backup your analysed data, so why should you not be able to do the same on iOS devices? Only a limited number of apps offer data backup, either within the app (such as DJ Player and Red Bull BPM DJ) or via iTunes filesharing when the device is connected to a host machine. This is useful if you want to ensure your efforts have not been wasted and also handy if you want to setup a second iOS device with the same cues, loops etc.

  

• Custom music library access – This is my favourite subject for iOS DJ apps! Take a look at the screenshot of the Track Load screen from the next version of the Red Bull BPM DJ app (it’s also the same on DJ Player). You get all the information you could possibly need and the ability to sort on crucial information such as BPM and comment (in case you’ve stored the harmonic key as the comment metadata). The screen displays the duration of the tracks as well as a tiny picture of the artwork. Down the side of the screen the index means you can jump to a particular group of tracks immediately without scrolling down a huge list. All of this helps to quickly locate the next track to play, giving you more time for other activities like applying effects or playing with loops
• Batch analysis – The idea behind this is to get the iOS device to do all the heavy work of calculating BPM, waveform and beatgrid for every track prior to using the device in a mix. Your tracks would all load instantly and the device is less exposed to memory issues. The note of warning here is that when processing your tracks, the app will be caching every track loaded into it, so if your music library is large perhaps it isn’t such a great idea.

Conclusion

As the iOS hardware and operating system mature, developers will continue to make best use of new features available, and the wishlists of DJs will expand further.

There are a huge number of other features which are likely to become increasingly popular, such as iCloud and iTunes Match support, and audio copy and paste support, the latter meaning you can create a beat or track in one app and copy the audio onto a deck in your DJ app. (Incidentally, djay has both of these).

Have we missed any features you think iOS DJ apps must have? Would you be happy to pay via in-app purchasing for extra features? How far off being a mature DJing platform do you think iOS is? Please let us know your thoughts in the comments.