How To Record A Grand Piano

August 22, 2016 Joff Winks

How do you record a grand piano? What mics work well, and where do you place them for that jaw-dropping ECM piano sound?

I recently finished a piano recording at the Jacqueline Du Pre music building, Oxford, and in this blog, I share some of my preferred techniques.

Recording A Piano

Recording a grand piano is a challenging job! In its concert form, the instrument is a formidable 7ft long and sometimes as much as 9ft.

Spanning from A0 with an earth-shaking frequency of 27.5Hz up to C8 with a fundamental frequency of 4186Hz, the grand piano has a broader note range than any other instrument in the orchestra. The harmonics and overtones reach way beyond the top C at 4186Hz, and capturing the piano in all of its magnificence will require mics with a well-balanced frequency response and an extended range if using anything other than a condenser design.

The grand piano has a lid designed to be much more than a simple cover for the strings and internal mechanisms. The piano lid attenuates the volume and modifies the timbre, imparting a directionality to the projection of the piano. As such, the player sits perpendicular to the audience with the lid opening towards the auditorium. When two pianos are used together in concert, removing the lids of both pianos allows the instruments to be fitted together like jigsaw pieces.

Recording the piano often requires working underneath the lid, especially if the piano is part of a band arrangement or a high degree of separation is required. However, recording the instrument without placing mics directly underneath the lid is possible, and this technique is often employed when the piano is playing as part of a classical ensemble.

Let's focus on recording the piano with the mics placed underneath the lid.

CLOSE MICS

Generally, the first mics I set up are directly above the piano hammers. The resultant recording should be nice and bright with plenty of attack, which is very helpful for cutting through a busy mix. Choosing the right mic for the job is crucial, and I favour using a matched pair of small diaphragm condensers with omnidirectional capsules.

There are many off-axis reflections underneath the piano lid, and using an Omni pattern mic is beneficial in this situation. The complex sonic environment underneath the piano lid requires a well-behaved mic with good handling of off-axis sources. As well as coping with the off-axis reflections, the Omni-pattern capsule design exhibits a flatter frequency response when working at close distances - Omni mics are immune to the bass proximity effect, which affects directional patterns.

With the lid still on the piano but opened fully, place the mics as a spaced pair pointing towards the lower strings on the left side and the upper strings on the right-hand side and at a working distance of between 6" to 1'. As with all recordings, it's wise to make a series of tests, adjusting the mic placement methodically and comparing the resultant recordings. A smartphone camera is a good tool for documenting the mic positions.

Note: When using a spaced pair, use the 3 to 1 rule - The mics should be three times wider apart than the distance from the instrument. So at a 1' working distance, the mics should be 3' apart, guaranteeing good stereo correlation and good mono compatibility.

This setup creates a balanced stereo recording with a clear and well-defined movement between left and right-hand passages.

Now that the mics are placed well over the hammers, it's time to fill out the bass end a little. Moving to the opposite end of the instrument, you can find a series of good mic positions over the bass strings, even over and around the sound holes that run along the curved edge of the piano harp. I use a single large diaphragm condenser in Omni configuration to mic the bass strings at about the same working distance as the spaced pair over the hammers. This mic helps to round out the timbre and balance the recording.

With these three mics in place, it's time to add the ambient mics, but before moving on to the room mics, let me show you another brilliant technique for making a stereo recording using two bi-directional (figure 8) ribbon mics. I start with my SE Electronics R1 ribbon mics mounted on a wide stereo bar. The mic capsules are placed at 90 degrees to one another, forming a Blumlein Pair (if you're unfamiliar with the term Blumlein Pair, follow the link to buff up your knowledge). Place the mic above the piano hammers on a long-boomed mic stand with a counterweight to balance the arm. The ribbon mics, whilst not having the full range of a condenser, have an extended frequency range and are famous for sounding smooth and silky, especially at the top end, where other mics can sound harsh or brittle.

With the Blumlein pair in this position, the stereo image is natural, if a little less focused than the spaced pair, but with a gorgeous balance of the close string and hammer sound and a little room ambience.

ROOM AND AMBIENT MICS

The next mic I like to set up is the Pianist Perspective Mic. Essentially this room mic captures the piano as heard from the pianist's perspective and helps the recording sound natural.

Place a mic behind the player slightly to the right or left with a clean line of sight between the mic and the instrument. A directional mic can help to pinpoint the source more easily whilst remaining focused and not too ambient. I would suggest a working distance of between 3 and 6 feet.

If working in a good-sounding room or hall, you want to capture all of the natural resonance and reverberation. The Jacqueline Du Pre music building has a nice-sounding concert hall seating around 200 people. The ceiling is pyramidal and reaches upward of 10 metres, and there is a gallery running around three edges of the building, three or so metres above the main seating area.

For the ambient recording, I start with a matched pair of small diaphragm cardioid condensers in an ORFT configuration - Two mics set on a stereo bar with the capsules pointing away from one another at an angle of 110 degrees or so. The mic capsules should be around 15cm apart. I recommend making a series of test recordings, methodically moving the mics farther away from the piano until finding the sweet spot.

Note: Using white gaffer tape to mark the mic stand positions on the floor is helpful as you move the stand. Recreating the mic position can be difficult without marking off as you go.

I ended up settling for placing the ORFT array in the gallery facing directly at the soundstage.

TIME TO LISTEN

With everything set up, we can listen to each mic or stereo pair to compare and contrast the different sounds of each position.

Note: The examples below have no post-production, dynamic processing or eq. The SE Electronics R1 Ribbon mics run through two TLA tube mic pres, and the remaining mics are running through my MOTU 896HD audio interface pres.