How to Master a Song Built From Suno Stems
Published · by Loopin
You don’t master stems; you mix them into one clean bounce with 3–6 dB of headroom, then master that file once. Get the kick-and-bass relationship right before the bounce and the master takes two minutes.
Set the gain on every stem before anything else
Suno stems usually arrive at whatever level they had in the original render, which means some are hot and some are tiny. Put a trim or clip-gain on each one so no single stem peaks above about −12 dBFS on its own. With 8–12 stems summed, that leaves the mix bus peaking somewhere around −6 to −3 dBFS, which is where you want it.
Do this with gain, not the faders, so your faders stay near zero where they’re easiest to ride. If the master bus is already clipping before you’ve done any processing, turn every stem down by the same amount rather than putting a limiter on the bus.
Lock the kick and bass together first
Regenerated or separated bass stems often carry a slightly different low end from the original mix: a bit more sub, a bit less punch, or both. Solo kick and bass, and decide who owns the lowest octave. In most pop and hip-hop, the bass or 808 takes 40–60 Hz and the kick sits at 60–100 Hz; cut 2–3 dB on one where the other lives.
Then high-pass every stem that isn’t kick or bass at 80–120 Hz. Pads, guitars and backing vocals carry low rumble in AI renders that you can’t hear on its own but that eats limiter headroom later. This one move buys the master 1–2 dB of clean loudness.
Glue with the bus, not with a limiter
A gentle bus compressor on the full mix — 2:1, slow attack around 30 ms, auto or 100 ms release, 1–2 dB of gain reduction on the chorus — makes stems that were split apart feel like one performance again. That’s the glue people are chasing when they say separated stems sound “disconnected”.
What to skip: a limiter or a clipper on the mix bus. It’ll make the mix sound finished while you’re working and leave the mastering stage with no transients to shape. Our post on limiters on the mix bus covers when that rule bends.
Bounce one stereo file with these settings
Export a 24-bit WAV at the project sample rate, peaking between −6 and −3 dBFS, with the bus compressor on and nothing after it. Include half a second of silence before the first note and cut the file a second after the last reverb tail. Don’t normalise it.
Listen to the bounce once, all the way through, on headphones. Stems that were fine on their own sometimes click at edit points or flam against the drums when summed; you want to catch that in the mix, not the master. If you haven’t split the song yet, start with what to do after Suno Advanced Split.
Master the bounce and judge it level-matched
Drop the WAV into the free online mastering tool and start with the default feel: a 16-bit WAV at about −14 LUFS with a −1 dBTP ceiling, which suits Spotify and YouTube. Use the loudness-matched Original-vs-Mastered A/B, so the master has to win on tone and punch rather than just volume.
Then try two contrasting feels on the same bounce. Warm if the stems sound thin, Crisp if the vocal is buried, Punchy (around −11 LUFS) if it’s a hard-hitting record. If none of them fixes a problem, the problem is in the mix: go back to the stems, fix it there, and master the new bounce free. There’s no cap on re-masters, so iterate.
Frequently asked questions
Should I master each Suno stem separately?
No. Mix the stems into one stereo bounce with 3-6 dB of headroom and master that. Processing each stem like a master makes the sum harsh and over-compressed.
How loud should my stems mix be before mastering?
Peaks between -6 and -3 dBFS on the mix bus, with no limiter. Integrated loudness will usually land somewhere around -20 to -16 LUFS, which is fine.
What format should I bounce Suno stems to?
A 24-bit WAV at the project sample rate. It gives the mastering stage a lossless file with headroom; the master itself can then be exported as a 16-bit WAV for distribution.
Why does my Suno stems mix sound thinner than the original?
Usually the bass stem lost some low-mid body or the kick and bass are cancelling. Solo them together, check polarity, and give each its own range: bass around 40-60 Hz, kick around 60-100 Hz.
What LUFS should a Suno stems master be?
Around -14 LUFS integrated with a -1 dBTP ceiling for streaming. Louder genres can sit near -10 to -11 LUFS if the level-matched A/B still sounds punchy.
Can I master Suno stems without a DAW?
You need something to sum the stems into one file, even a free DAW. Once you have the stereo bounce, mastering itself needs no DAW.