Bit Rate Explained for Digital DJs

I was talking to a friend recently who is getting his first DJ controller. Inevitably, the conversation turned to the music he’ll be using. Up to now, he has mainly been streaming from Spotify, and he selected Algoriddim’s DJay Pro specifically because of its integration with the popular streaming platform. I told him that’s all well and good, but that it would behoove him to use high-quality audio files from his personal collection at gigs.

All Audio is NOT Created Equal

The thing is that not all audio is created equally. The quality of audio files varies wildly out there in the world, so a digital DJ should be familiar with the basics of bit rate.

Bit rate refers to the amount of information present in one second of audio. The higher the bit rate of a recording or stream, the more detailed the sound produced on your system – to the degree that your system is capable of reproducing the sound, of course.

A Real-World Example

To put it in perspective, another friend of mine once played an hour DJ set at a certain bar I used to play. Not only did the volumes of each song relative to one another continually fluctuate, but the depth of the sound did as well. One song sounded vibrant while the next song sounded rather flat. It’s a difference one probably would not have noticed had they not been played side by side, or on a lesser audio system.

I asked him later if he had ripped some of his music from YouTube, and he admitted he had. Ethics aside, ripping music from YouTube is a bad idea for DJs because YouTube’s audio is compressed to 126 kbps. When compared to his legitimately purchased high-quality MP3 files with a bit rate of 320 kbps, it’s easy to see why it would sound trashy by comparison.

Having Standards

It’s important for any DJ with aspirations to have quality standards for the music they use. Typically, that standard is 320 kbps MP3 files. It’s the standard because it provides the most bang-for-your-buck when it comes to the file size vs. audio quality tradeoff. 320 kbps MP3’s sound great on a big system – arguably indistinguishable from the monster-sized lossless formats. Of course, if you have the space (and the money – lossless audio files from services like Beatport are significantly pricer), you can go lossless all the way if you so choose.

Personally, the lowest quality files I would consider using are 256 kbps MP3s. They are of lesser quality than the 320 kbps standard, but the difference in quality is small enough to be acceptable to me. That, and I don’t have too many files of that quality. However when the quality dips to 192 kbps or below, the difference is great enough to be noticed by the audience – particularly when played back to back with a high-quality file.

CBR vs. VBR

Diving a little bit deeper into bit rates, we find there are actually two types; CBR and VBR. This stands for Constant or Variable Bit Rate. Constant Bit Rate is what is generally referred to when we talk about file compression. Variable Bit Rate is a means by which one can further compress an audio file by reducing the bit rate for silent or quiet passages and increasing it for rich, loud passages.

Generally, I would suggest a digital DJ stick to CBR files. They are more common and are less likely to be incompatible with hardware.

Apple’s .AAC Files

The MP3 file type is 24 years old. By tech standards, that is ancient. AAC is another compressed audio file type developed by Apple. This is the type of file you get from iTunes. AAC is much newer, and thus was developed to be of higher quality than its predecessor. As such, a 256 kbs AAC file is of comparable quality to a 320 kbps MP3 file, so don’t throw out your iTunes purchases!

The Short Version

Digital DJs ought to use at least 320 kbps MP3 or 256 kbps AAC files for gigs. Any less and you begin to run the risk of sounding trashy. Fortunately, these files are easy to find and create. If you have CDs of your music (commercially written to the medium as lossless WAV files), you can choose to encode them as 320 kbps MP3 files.

For those of you looking to hear the difference between different bit rates, you can visit this page and scroll to the bottom to take a bit rate discernment test. The goal: pick out the lossless audio.

-Chris Lazaga
AudioMunk

Are you confused when it comes to digital audio? Drop me a question on my contact page and I’ll help you out – I may even produce an article on your topic!