The Controls

ControlWhat It Does
ThresholdLevel at which compression engages. Signal below passes through untouched. Lower = compresses more often.
RatioHow aggressively signal above threshold is reduced. 4:1 means 4 dB over threshold yields 1 dB out.
AttackHow quickly the compressor engages after threshold is crossed. Fast catches transients. Slow lets punch through.
ReleaseHow quickly the compressor lets go after signal drops below threshold. Too fast = choppy. Too slow = squashed.
Makeup GainRestores overall level after compression reduces peaks. Match output level to input level as a baseline.
KneeHard knee engages abruptly at threshold. Soft knee eases in gradually — more natural on vocals and acoustic sources.

Starting Points by Source

SourceThresholdRatioAttackReleaseNotes
Kick drum-20 dB4:110–30 ms100–200 msLet the transient punch through
Snare-18 dB4:15–15 ms80–150 msFast but not instant
Bass (DI)-18 dB4–6:130–50 ms150–250 msSmooth out note-to-note variation
Electric guitar-20 dB3–4:120–40 ms100–200 msEven out pick dynamics
Acoustic guitar-18 dB3:130–50 ms150 msGentle, preserve natural feel
Vocals-20 dB3–4:110–20 ms100–200 msSoft knee, aim for 4–6 dB GR
Keys-20 dB3:120–40 ms150 msLight-handed

GR = Gain Reduction. Watch the GR meter on the DM7. For most sources, 4–6 dB of reduction on peaks is appropriate. Consistently seeing 10+ dB means threshold is too low or ratio too high.

On the DM7

Access compression via the Dynamics section on the selected channel. The GR meter is your primary feedback tool — use it.

The mix bus compressor is off-limits unless you've talked to Matt. Heavy bus compression affects the entire mix and is difficult to undo mid-service.

Examples

Scenario: Vocalist alternates between soft verses and loud choruses. Without compression, you're constantly riding the fader. Set threshold around -20 dB, ratio 3:1, soft knee — the compressor handles peak control and you focus on the overall mix.

Scenario: Kick drum loses its punch after compression is applied. Attack is too fast — the compressor is clamping down before the transient gets through. Slow the attack to 20–30 ms to let the initial hit breathe.

Related Concepts

Related KB Entries

Sources / Further Reading

  • Yamaha DM7 Reference Manual — Dynamics section