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Suno tracks sound hissy or metallic. Here is what is actually there.

Updated 2026-09-06

Three complaints come up more than any other about Suno exports: a hiss that sits on top of everything, a metallic ring in the upper mids, and a vocal that sounds like it was sung into a cardboard box. They are not imagination. They show up on a spectrum analyzer every time.

What the analyzer shows

The hiss is broadband noise between roughly 8 and 14 kHz that does not follow the music. On a real recording, noise at that height rises and falls with the performance. On a generated track it stays flat, which is why your ear locks onto it.

The metallic ring lives between 3 and 6 kHz. It is a set of narrow resonances the generator repeats across the whole song, so the same three or four frequencies keep poking out of every snare and every consonant.

The boxed vocal is a bump around 300 to 500 Hz combined with the top end stopping dead near 16 kHz. Together they make a voice feel close and small at the same time.

What does not work

A high shelf boost makes the hiss louder before it makes the vocal brighter. A wide cut at 4 kHz kills the ring and the presence with it. Loudness on its own makes all three worse, because a limiter pushes the noise floor up with the music.

What works

• Measure first. Find the exact ring frequencies on this file, not a preset. They move between Suno versions.
• Cut the ring with narrow notches, one or two dB each, no wider than a third of an octave.
• Treat the hiss with a gentle downward expander above 8 kHz that only opens when the music is there. That keeps cymbals and air.
• Rebuild the top end above the cutoff from the harmonics that exist, instead of boosting a band that has nothing in it.
• Then master. Loudness last, with true peak held at or under -1 dBTP.

Burnish does exactly this order, measures your file before it touches anything, and prints each move in dB on the report so you can check it against your own ears.