Why Does My Master Sound Distorted?
Published · updated · by Loopin
Distortion that appears only after mastering almost always comes from one of four places. Working out which one you have takes about two minutes and saves you from guessing.
First: was it already there?
Before blaming the master, listen to the mix on its own at a matched level. Turn the master down until the two sound equally loud, then A/B. Distortion that exists in both was baked in during mixing or recording, and no mastering decision will remove it.
This step gets skipped constantly and it is the one that saves the most time. A clipped vocal take, a bass DI that overloaded the interface, an overdriven sample — mastering makes these more obvious because it raises the average level, but it did not create them.
Cause one: the mix arrived too hot
If your mix bus is already peaking near 0 dBFS, the mastering chain has nowhere to work. Every EQ boost pushes further into the ceiling and the limiter ends up doing several decibels of reduction just to get back to legal.
Aim to hand over a mix peaking around −6 to −3 dBFS with no limiter on the master bus. This is not superstition — it is simply giving the next stage room. If your mix is already limited, the mastering stage is compressing something that has been compressed, and the artefacts stack.
Cause two: too much limiting
Ask how much gain reduction the limiter is doing. One to three decibels is healthy. Six is aggressive. Ten and you are not limiting, you are distorting on purpose — transients get flattened into square-ish shapes and the result is a gritty, fatiguing edge that sits on top of everything.
The tell is that it gets worse in the loudest sections and disappears in quiet ones. If the verse is clean and the chorus is crunchy, the limiter is the problem. Lower your loudness target rather than fighting it.
Cause three: inter-sample peaks
Your file can measure 0.0 dBFS on a sample peak meter and still exceed full scale when a converter reconstructs it as sound. These overshoots clip on playback even though the file itself looks legal.
The tell here is distortion that appears on some devices and not others — clean on your interface, crunchy on a phone or a cheap Bluetooth speaker. Fix it by setting a true-peak ceiling of −1 dBTP and re-rendering, not by turning the finished file down.
Cause four: the encoder did it
Streaming platforms deliver lossy audio. MP3 and AAC encoding does not preserve peaks exactly, and a master sitting at or near 0 dBFS routinely comes back from an encoder above full scale.
If your WAV is clean but the uploaded version is not, this is your answer. The same −1 dBTP ceiling fixes it. Test it yourself by encoding an MP3 at 128 kbps and listening — if the distortion appears there and not in the WAV, the encoder is the culprit.
Frequently asked questions
How much gain reduction is too much on a master?
One to three decibels is healthy, six is aggressive, and beyond about eight you are trading transients for loudness you will not keep once streaming normalises playback. If the distortion appears only in loud sections, this is almost certainly the cause.
Why does my master sound fine on my speakers but distorted on my phone?
Inter-sample peaks or lossy encoding. Both produce distortion that only shows up after the file is reconstructed or re-encoded, which is why it varies by device. A -1 dBTP ceiling addresses both.
How loud should my mix be before mastering?
Peaking around -6 to -3 dBFS with no limiter on the mix bus. The exact number matters less than leaving genuine headroom so the mastering chain has somewhere to work.