Piano Miking
The lid sets width and brightness; the spacing of two mics decides what survives in mono.
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The lid comes first
Half of a grand piano's sound leaves through the lid. Fully open is brightest and widest, and it also gathers every flaw in the ceiling and the walls. Half stick tightens the midrange for pop backing; a closed lid gives isolation but sounds boxy, so remove the front panel or reach in over the soundboard. Decide how much isolation the session needs, set the lid, then choose microphones.
| Lid | Tone | Isolation | Mic position |
|---|---|---|---|
| Fully open | Bright, wide, long tail | Poor | 20–30 cm above the strings |
| Half stick | Solid midrange, medium width | Medium | Over the mid-treble, off the hammers |
| Closed | Dark, close, no air | Good | Front panel off, or near the soundboard |
What the spacing costs
A spaced pair hands the bass and treble registers to separate mics. The width is natural, at the price of a possible hole in the middle. Start 60 to 100 cm apart and listen back in mono. Sound travels about 340 m per second, which is 34 cm per millisecond; the wider the pair, the earlier the midrange drops when the channels fold together. XY is stable but narrow, and ORTF at 17 cm and 110 degrees sits between the two. Keep the mics off the hammer row or the attack turns brittle; angle them 10 to 20 degrees and hammer, string and soundboard settle into balance.
The room and the mechanism are part of the take
An open lid throws sound up and sideways, so ceiling, walls and floor all reach the microphones. Keep the piano half a metre or more from the wall and the low end stops pooling under the soundboard. Rugs, felt and a cloth on the bench mute pedals, dampers and clothing. On a solo recording the pedal lift and the damper fall belong to the performance; behind a pop vocal the same noises are clutter, and moving a mic beats any denoiser.
When two mics make it worse
Small room, piano against a wall, lid wide open: the second mic mostly collects another reflection rather than more detail. Thinning in mono, low end that wanders between speakers, a piano that steps back as soon as the vocal enters — phase explains all of it, and a widener will not repair it. Only moving a mic will. For solo and classical work that needs body and air, one close mic plus a room mic two metres out usually says more than a close pair.
Listen in the library
All tracks from midicn-lib — inline badge is the license tier (C1 commercial / C2 non-commercial / C3 study only).
Along the same line
Sources
- Eargle, The Microphone Book, 3rd ed., piano chapters
- Everest, Master Handbook of Acoustics, low-frequency treatment in small rooms
- DPA Microphones, 钢琴拾音指南（厂商文档）