The 5 Most Common Mix Problems (And How to Fix Them)

After analyzing hundreds of mixes on MixDiagnose, the same problems show up over and over. Here are the 5 most common — and exactly how to fix them.

1. Muddy Low-Mid Buildup (200-400 Hz)

This is the #1 issue. Almost every amateur mix has it.

Symptom: The mix sounds dull and unclear. Instruments blur together. You can't separate the bass from the guitars.

Cause: Too many tracks occupying the 200-400 Hz range simultaneously. No high-pass filtering on non-bass instruments.

Fix:

# High-pass filter everything except kick, bass, and sub
vocals: 80-100 Hz
guitars: 80 Hz
synths: 40-60 Hz

# Then cut 2-3 dB at 300 Hz on tracks that still sound muddy

The difference is night and day. I've seen mixes jump 15 points on the Mix Score just from fixing this one issue.

2. Over-Compression (Crest Factor < 6 dB)

Symptom: The mix has no punch. Drums don't hit. Everything is the same volume. It sounds "small" despite being loud.

Cause: Too much bus compression. The dynamic range that makes music feel alive has been squashed out.

Fix:

• Remove or reduce mix bus compression (2:1 max, 2-3 dB GR)
• Compress individual tracks instead
• Target crest factor ≥7 dB
• If you need loudness, achieve it in mastering, not mixing

I analyzed 10 hit songs and every Grade A track had ≥7 dB crest factor. Every B-grade track was below 7. Full data here.

3. Harsh Highs (2-5 kHz)

Symptom: The mix sounds piercing. Listeners want to turn it down. It's fatiguing after a few minutes.

Cause: Too much energy in the 2-5 kHz range. Usually from:

• No de-essing on vocals
• Electric guitars with natural resonance at 3-4 kHz
• Synths with bright waveforms not filtered

Fix:

1. De-ess vocals (target 5-8 kHz for sibilance)
2. Cut 1-2 dB at 3-4 kHz on harsh instruments
3. If the whole mix is harsh, try a gentle 1 dB cut at 4 kHz on the mix bus

4. No Headroom (Mix Too Loud)

Symptom: Mix is at -8 LUFS with true peaks at -0.2 dBTP. There's no room for mastering.

Cause: Mixing too hot — the mix is essentially pre-mastered. A limiter on the mix bus is crushing transients.

Fix:

• Target -18 to -14 LUFS for a pre-master mix
• Keep true peaks below -3 dBTP
• Remove the limiter from the mix bus
• Leave at least 6 dB of headroom

5. Stereo Phase Issues

Symptom: Mix sounds wide on headphones but disappears on speakers. Elements sound hollow or phasey.

Cause: Phase cancellation from stereo widening plugins, duplicated tracks with timing offsets, or poor mic placement.

Fix:

1. Check mono compatibility — sum to mono and listen
2. Keep low frequencies (below 120 Hz) in mono
3. Remove stereo widening plugins and see if the problem goes away
4. Use a correlation meter — should stay above -0.5

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Want to check your mix for all 5 automatically? Upload to MixDiagnose and get an instant Mix Score (0-100) with specific issues flagged by severity.

Or use the CLI:

pip install mixdiagnose
mixdiagnose analyze my-mix.wav

Fix your mix before you master it.