# Piano Microphone Techniques Recording piano is widely considered one of the most challenging tasks in audio engineering due to the instrument's large physical size, complex harmonic content, and highly directional sound radiation patterns.[^1] ## Understanding Piano Sound Radiation ### Frequency & Dynamic Range[^2] **Fundamental frequencies:** - Lowest note: 27.5Hz (A0) - Highest note: ~4100Hz (C8) - Harmonics extend beyond 10kHz **Dynamic range (measured at 10 meters):** - Loudest: 85dBC (bass) to 70dBC (treble) - Quietest: 50dBC (bass) to 37dBC (treble) **Harmonic characteristics:** - Lower two octaves: Fundamentals can be 25dB below upper harmonics - Upper register: First partial typically 20dB below fundamental (nearly sinusoidal) - Overtones are NOT perfectly harmonic due to percussive nature **Mechanical noise components:** - Lower notes: 200-500Hz - Middle notes: ~200Hz - Upper notes: ~1kHz (most audible, not masked by fundamental) ### Grand Piano Sound Radiation Patterns[^3] **Low frequencies (<250Hz):** - Largely symmetrical radiation - 5dB stronger behind piano (player's left) than front - Sound localizes below instrument - Main lobe directed forward over 60° angle to player's right **Mid frequencies:** - Lid becomes directional reflector (typically 38° angle) - Best projection: Forward (player's right) and upward (horizontal to 55° up) - Directly above piano: Duller due to HF screening from lid - Rear bottom quarter: Fundamentals weakened (up to 10dB down) **High frequencies:** - Strong directivity 15-35° from horizontal toward front (following lid angle) - Outside this range: Upper harmonics can be 10dB down - Horizontal plane: Main lobe straight forward + secondary lobe 30° toward bottom - Lobes only 10° wide at highest frequencies = narrow "sweet spot" **Mechanical noise:** - Much stronger behind piano than in front - **Never mic a piano from behind** for musical purposes ### Lid Position Effects[^4] **Fully open (long stick, ~38°):** - Maximum brilliance and clarity - Strong upward/forward radiation lobes - Best high-frequency projection **Half open (short stick, ~10°):** - Similar radiation pattern to fully open - Slightly reduced amplitude, especially HF - Slightly duller but maintains projection characteristics **Closed:** - Significantly duller sound (reduced HF radiation) - Overall level decrease - No upward lobe; stronger lobe toward player through music stand opening - Loses brilliance and clarity **Removed:** - Radiation pattern disrupted - Reduced horizontal energy, increased vertical - Duller and thinner tone (pronounced LF reduction) - Main HF lobe: 60° back from frontal axis (player's right shoulder) - Very dependent on ceiling proximity/reflectivity ## General Microphone Selection Considerations **Microphones inside** the instrument will pick up unwanted pedal and hammer sounds in addition to the music, but they get a brighter, closer sound. **Microphones outside** but near the side of the instrument "looking in" can also hear reflections from the top. That can be good or bad, depending on what you want. **Microphones away** from the instrument will record the piano and the room. If your room sounds good, and you don't need a very close sound, this is a safe method for recording a balanced piano as the sound of the instrument doesn't really exist properly until you get some feet away from it. **Miking from the side** usually means that the higher notes will come out louder. Miking inside the case will tend to emphasize the middle octaves, which could be good for some music styles and not for others.[^5] **Essential microphone characteristics:**[^6] - Smoothest possible off-axis response - Extended bass response (large-diaphragm condensers preferred) - Avoid mics with presence peaks (unless intentional for specific context) - Examples: Neumann KM86, U47, M49; AKG C414 ## Steve Albini Method ![[Piano Microphone Techniques .excalidraw.svg]] ## Al Schmitt Method ![[Piano Microphone Techniques _0.excalidraw.svg]]