Common Mix Problems

Dull, harsh, unstable, pumping, flat, five symptoms and the first move for each.

Related

EqualizerCompressorPhase Check

The problem

AI mixes fail in a handful of ways. Dull lows, harsh highs, an unstable image, pumping compression, an overall flatness. Each symptom has a few usual causes, and the first move decides how long the repair takes. The moves below can each be checked immediately.

How it works

Dullness is usually a 200 to 500 Hz pile-up from pad and bass overlapping, not a lack of treble. Harshness is usually too much between 2 and 5 kHz, coming from saturation, limiting and sibilance. An unstable image comes from inconsistent phase or mismatched left and right reverb. Pumping comes from a slow compressor release or too much sidechain. Flatness comes from dynamics being removed early. Symptoms disguise each other, since dullness can come from phase cancellation and harshness from limiter distortion, so run a mono check and a bypass comparison before naming the cause. Order matters as much as the diagnosis, so rule out phase and level before touching tone.

Practice

Five symptoms, one first move each.

• Dullness, solo bass and pad in mono, high-pass one of them above 120 Hz, then decide whether a narrow cut at 300 Hz is still needed
• Harshness, check saturation and limiting, lower gain reduction by 1 dB, then apply a dynamic cut at 3 to 6 kHz on the vocal
• An unstable image, flip polarity, align timing, and make the reverb send mono
• Pumping, set release under 200 ms or halve the sidechain depth
• Flatness, write volume automation before considering compression

If the symptom survives two moves, stop and listen to the arrangement, since many problems live in the material and plugins only hide them. Change one variable at a time and return to the full mix for ten seconds.

What to listen for

In the organ hymn, hear whether the low end has become one lump, since sustained notes expose a pile-up best. In Shostakovich's fugue, hear whether the dense high register turns harsh. In the 65 BPM rock groove, hear whether compression makes every beat sit down. In Ravel's Le gibet, hear whether the bell stays in place, because instability starts with sustained tones. In all four, confirm the symptom before touching anything.

Sources

• 混音症状与首要动作的对应，依混音诊断通识核对，未抄文本
• Symptom-to-first-move mapping, based on general mix diagnosis practice, no text copied

Used for fact-checking only; all prose is original.