Digital DJ Tips forum member Eledamiri writes: “I was watching your video about digital music quality the other day and then I wondered what exactly variable bitrate (VBR) is? Every now and then I encounter files with 205 VBR, 240 VBR and so, especially when I download DJ sets from SoundCloud. So do you know if they are so much different from 320kbps MP3s? I’m more of a listener than a DJ, by the way, but this community is great, I spent a lot of time reading the stuff here.”
Digital DJ Tips say
Thanks for your kind words! OK, here’s the difference. VBR is where the encoder (the software that turns analogue audio into a digital MP3) is allowed to choose the optimum bitrate for any particular section of music, as it encodes it. In short, it’s a way of reducing file size without reducing quality, by reducing the bitrate when the musical information is simple in a track, and increasing it only where it is needed.
In the early days of VBR, poor encoders produced famously bad VBR files that tarnished the reputation of the technology somewhat, but nowadays most audio technicians think it works really well. However in these days of ever-increasing and ever-cheaper storage, it’s becoming less important. the advantage is still there, though: an MP3 encoded with maximum 320kbps and VBR set should in theory be smaller than a 320 CBR (constant bit rate) MP3 – but sound exactly the same.
Trust your ears, but a VBR file at a reasonably high MP3 bitrate should sound just fine.
Do you use CBR or VBR when you encode MP3s? Have you had any compatibility or sound quality issues with VBR MP3s? Please share your thoughts in the comments.