Comb Filtering
Direct and delayed copies summing into a response with regular peaks and notches
Related
Comb filtering appears when a direct sound sums with a short delayed copy, producing evenly spaced peaks and notches like the teeth of a comb. A shorter delay widens the spacing; the first notch falls where the delay equals half a cycle.
It commonly comes from two microphones hearing one source, early reflections off a desk or console, and very short delay effects. The result sounds hollow, thin or oddly coloured, and it shifts as the listener moves. Remedies include changing distance and time alignment, reducing duplicate pickup, or treating the reflecting surface.
The usual mistake is expecting an equaliser to repair it. A fixed notch can be filled, but move the listening point and the pattern moves; fix timing and paths first, then consider EQ.
Sources
- 短延迟叠加与梳状滤波，参 Everest & Pohlmann, Master Handbook of Acoustics 与 Huber & Runstein, Modern Recording Techniques；本文为原创表述
Used for fact-checking only; all prose is original.