Use a narrow Q when cutting and a wide Q when boosting

A widely used equalization heuristic that shapes how EQ moves sound. When you cut a problem frequency, a narrow Q (bandwidth) surgically removes only the offending band while leaving surrounding frequencies intact — you want the cut to be precise so it does not thin out the whole sound. When you boost, a wide Q sounds more musical and natural because it lifts a broad region gently rather than creating a resonant, honky peak; a narrow boost tends to sound artificial and can ring. The underlying reason is perceptual: narrow boosts draw attention to themselves as an obvious coloration, whereas broad boosts read as tonal character. The corollary tip is that adding a small amount at two frequencies is usually better than a large amount at one. This is a starting-point rule, not a law — some corrective boosts (feedback notches, deliberate resonances) invert it.

Examples

To remove a boxy resonance around 400 Hz on a guitar, use a narrow bell and cut a few dB. To add air and sheen to a vocal, use a wide high-shelf or broad bell around 10-12 kHz rather than a narrow spike. A narrow 6 dB boost at 3 kHz sounds harsh; the same 6 dB spread over a wide band around 3 kHz reads as presence.

Assessment

You need to (a) remove a ringing resonance from a snare and (b) add warmth to a thin acoustic guitar. For each, state whether you use a narrow or wide Q and whether you cut or boost, and explain why the opposite Q setting would sound worse.