These two terms get thrown around constantly, and a lot of musicians use them interchangeably. They're not the same thing. Understanding the difference will change how you think about your recordings.
Mixing: making everything work together
Mixing starts with individual stems (separate tracks for each instrument) and ends with a single stereo file.
The job of mixing is to make all the parts sit together so you hear a song, not a pile of instruments fighting for space. That means:
Volume balance. The vocals need to be loud enough to hear clearly. The bass needs to fill the low end without drowning out the kick drum. Every element gets its own level.
EQ (equalization). Each instrument occupies a range of frequencies. When two instruments share the same range, they mask each other. EQ carves space so the bass guitar and kick drum can coexist, the vocals can cut through the guitars, and the cymbals don't eat the high end.
Compression. Compression evens out the dynamic range of a track. A vocalist who whispers one line and belts the next will have a huge volume difference. Compression tames those peaks so the quiet parts are still audible and the loud parts don't blow your ears off.
Panning. In a stereo mix, you can place instruments left, right, or center. Drums might be spread across the stereo field. Rhythm guitar goes slightly left, lead slightly right. Vocals sit dead center. This creates width and space.
Effects. These add character and depth. A dry vocal sounds like someone singing in a closet. A touch of reverb puts them in a room.
The output of mixing is a stereo audio file that sounds like a finished song.
Mastering: preparing for the real world
Mastering takes that finished stereo mix and prepares it for distribution.
Where mixing deals with individual instruments, mastering deals with the mix as a whole. It's the final quality control step.
Loudness. Your mix might be quieter than commercial releases. Mastering brings it up to a competitive level using limiting and gain. Streaming platforms like Spotify normalize loudness to around -14 LUFS. If your track is way below that, it'll sound weak next to everything else in someone's playlist.
Tonal balance. A mastering engineer (or algorithm) listens for overall frequency issues. Maybe the low end is a bit muddy, or the top end is a bit harsh. Subtle EQ moves correct these.
Consistency. If you're releasing an album or EP, mastering ensures all tracks have similar loudness and tonal character. Without this step, each song might sound like it was recorded in a different room (which it probably was).
Why you need both
Skipping mixing and going straight to mastering is like painting a house without priming it first. Mastering can't fix a bad mix. If the vocals are buried and the bass is boomy, no amount of mastering will save it.
Skipping mastering and releasing a raw mix is less catastrophic, but your track will sound quieter and less polished next to everything else on Spotify or Apple Music. Listeners might not know why, but they'll feel it.
How Bandmixr handles both
Upload your stems and Bandmixr handles mixing first: analysis, EQ, compression, panning, reverb, level balancing. You preview, tweak, and finalize.
Then you choose a mastering preset. Streaming mode targets -14 LUFS for platforms like Spotify. Standard mode is a bit louder for general release. Loud mode pushes harder for genres that demand it.
You can also just use the Bandmixr mastering feature if you have your own mix you want to master.