The Stereophile Test CD Track 10
 Frederic Chopin: Scherzo in b-flat, Op.31 (ADD) 9:49
Anna Maria Stanczyk (Hamburg Steinway piano)
Recording Venue: Derngate Centre, Northampton, England
Recording Date: September 22, 1983
Recording Engineer: John Atkinson
Microphone: Calrec Soundfield Mk.III, set to coincident figure-8s at 90 degrees
Recorder: ReVox A77 ¼" open-reel recorder at 15ips (CCIR EQ)
Transfer to digital: Nakamichi 1000 R-DAT
Digital Transfer Engineer: John Atkinson
Original commercial releases: 1984, Ensemble ENS 118 Real-Time cassette (Whitetower Records, 2 Roche Gardens, Bletchley, Milton Keynes, MK3 6HR, UK); 1985, Pronit M-0012 LP (Poland).
The Calrec Soundfield microphone is a single-point, multi-capsule design that was originally developed to make Ambisonic recordings. It is supplied with a sophisticated control center that, in addition to Ambisonic pickup, allows the user to select many different coincident stereo patterns. For this recording John Atkinson used the control center to synthesize a pair of figure-8 microphones pointing left and right with an angle of 90 degrees between them.
This gives an extremely accurate recreation of the original soundfield, but as such a pair of microphones picks up all the sounds to their rear as well as to their front, it is hard for the engineer to strike exactly the right balance between the direct sound of the instruments and the echoes of that sound from the hall's walls, ceiling, and floor: the "reverberation." Small forward and backward movements in microphone positioning also yield large changes in the recording's soundstage perspective. Regarding the tonal changes introduced by this microphone, they are relatively small when it is set to synthesized figure-8s. The recorded piano sound, however, is a both a little duller than the original, and slightly accentuates the mechanical noises of the piano keys and mechanism in the presence region. It is very true in the midrange and below, however.
The modern hall has a lovely, uncolored acoustic and the microphone position—10' in the air, about 17' from the Steinway piano, looking down the line of the lid—was chosen in order to capture a reasonable sense of its signature. The piano's keyboard was just to the microphone's left, which means that the piano image, when the recording is played back over good loudspeakers, should extend from the inside edge of the right loudspeaker to just left of center, the rest of the space being occupied by the hall. The piano image should sound as though it is behind the line joining the loudspeakers. If it sounds more forward than that, then the system is doing something wrong.
Piano recordings are also excellent for revealing midrange resonant problems in loudspeakers. Listen for notes that appear to jump forward at you, particularly in the first octave above the treble staff, which is where many drive-units have problems: tweeters at the bottom of their passbands, woofers at the top.
Incidentally, the quiet "Well done!" at the work's conclusion is from the Polish pianist's manager, who was standing to the far left of the microphone. On systems with superb soundstaging, his voice should appear to come from well beyond the lefthand speaker position. Why did he say "Well done!"? The Steinway had been provided for an evening concert performance of Rachmaninoff's Rhapsody on a Theme by Paganini by Alicia de Larrocha, and the hall's management had agreed that we could use it for this recording provided we did it after the concert. The session therefore started at 11pm; Anna turned in this powerhouse of a performance with the last of her energy at 4 in the morning!