Multiband dynamics fix a dynamic problem in one frequency region without touching the others

Full-band compression applies gain reduction across the whole spectrum whenever total level exceeds the threshold, so fixing a problem confined to one band overcorrects the rest — tightening a boomy low end also ducks the mids and highs. Static EQ, conversely, cannot address a level that varies over time. Some balance problems need both: a resonance that only pokes out at high note velocities, or a bass whose low-frequency energy varies with pitch while the midrange stays steady. A multiband processor splits the spectrum at crossover points and applies independent threshold, ratio, attack, and release per band — a useful mental model is treating each band as a separate mini-instrument with its own balance. Practical settings: reassess attack and release per band (highs move faster than lows), use only as many bands as the problem needs, avoid automatic makeup gain, and watch for phase cancellation between bands.

Examples

Proximity-effect bass buildup on a vocalist who moves: a low-band compressor at 20–200 Hz tightens the boom while 1–8 kHz presence and transient clarity are untouched. Acoustic guitar with a 200 Hz sound-hole boom and 5 kHz pick spikes: limit the low band for the boom and reduce transients in the high band for the picks, each independently. Other uses: de-essing in the high band only; taming resonant peaks that wander in frequency.

Assessment

Explain why a single full-band compressor cannot solve a low-frequency resonance that only emerges at high note velocities, and why a multiband is better than a full-band compressor for proximity-effect bass buildup on a moving vocalist. In a two-band treatment of an acoustic guitar, why might you set different attack times for the low and high bands?