We DJ at many Vermont weddings and events, and this topic occasionally comes up when a customer is shopping for a DJ. I know what you are thinking, it’s 2018 and everyone uses MP3s now. Are we really still having this debate? I’m afraid so. Some DJs still insist that “serious” DJs use CDs and “amateur” DJs use MP3s. These well-meaning but misinformed people have suggested that MP3 music sounds awful on a DJ system. Music recording, compression and perception are complex topics (especially for old-fashioned DJs who still use CDs). The quick answer is that the human ear is incapable of distinguishing between a properly encoded MP3 and a normal Audio CD.
Let’s start with some definitions (Oh, and this is your official nerd-content warning, for the quick answer, skip to the last paragraph):
WAV file: A WAV file is a music file designed for playback on a normal CD player. Almost all commercially produced audio CDs contain WAV files. This music has been compressed from the original recording format used in the recording studio. Most people don’t realize this, but even a commercially produced CD contains compressed audio files.
Music File Compression: This is the process by which music files are compressed so that they take up less space on your device. Whenever you compress music files, some loss of quality occurs. Fortunately, if this is done properly, the human ear is incapable of noticing a difference in the sound quality.
MP3: Simply stated, MP3 files are compressed audio files. The sound quality of an MP3 depends on how it was encoded (compressed) from the original music file. Modern encoders produce very high quality sound as long as the bit-rate is set at or above 128 kilobits per second. By the way, there are several other common formats for compressed music (Apple uses ACC files, for example). Rather than complicate this post too much, I’m going to lump these formats in with MP3s (with apologies to any audiophiles reading this).
Kilobits per Second: In the music world, this is a term used to describe how much sound information is captured on a digital recording. Generally, more kilobits per second result in more sound quality. The human ear is capable of recognizing quality problems in sound recorded at fewer than 128 kilobits per second (although some people with exceptional hearing can perceive a difference up to 192 kilobits per second). Most professionals who use MP3 music agree that files should be encoded at 192 kilobits/second just to be safe.
When you watch a movie, you know you are actually watching thousands of still pictures flashing across the screen. Each picture is slightly different from the one before and they all add up to what we perceive as motion. Music recordings behave much the same way. The sound on your CD represents millions of tiny “still” sound fragments. When played in rapid sequence, our ears/brains create for us the illusion of actual, real music. If a motion picture only uses one picture per second, the movie will appear very choppy and distracting. Likewise, if you hear an MP3 with a low kilobit/second rate, the music will not sound smooth and pleasing to your ears.
The Bottom Line: Music recorded at 192 Kilobits/second sounds the same to the human ear as music recorded at a billion Kilobits/second. The music you purchase from iTunes is encoded at 256 kilobits per second. Soundrock uses MP3 files and they sound great! We don’t have to keep a back table of CDs, we can switch songs with lightning speed, we can carry much more music and we don’t believe MP3s are newfangled technology that can’t be trusted. Take that, old fashioned DJ with your CD collection! I’m surprised you have internet access to read this.
But seriously, DJs should use whatever music format they are comfortable with. CDs are fine and so are MP3s. Both are compressed music files, and both sound equally great on an amplified system.