Fate, I Defy You: The Robert Silverman Liszt CD Page 2
Sonata was recorded in the same Albuquerque church in which we had recorded Concert. This is a relatively modern building: While the ambience is pleasant-sounding, the reverberation is not "bathroomy." The piano was placed on a small stage at the front of the nave. The microphone setup can be seen in the two photographs. (Ignore the fourth central mike in these pictures; it was a third omni mike that we used to produce the "Mapping the Soundstage" tracks mentioned earlier.) The two B&K omnis were spaced about 12' apart and pointing toward the roof. Used with the black (diffuse-field) grids, this results in an overall flat response for sounds arriving from the direction of the piano. The capsules were 52" above the top of the piano frame, following the line of the instrument's raised lid, with the left and right mikes 4' and 8', respectively, from a point on the front of the piano where the hammers strike the strings.
The B&K microphones were nearer to the body of the piano than the Schoeps.
For the central microphones, I chose to use the Schoeps KFM6 "Sphere," a favorite of engineers Peter McGrath (Audiofon, Harmonia Mundi) and Jerry Bruck (Posthorn Recordings). As can be seen from the photo, the Sphere consists of a head-sized plastic globe with flush-mounted omnidirectional microphone capsules pointing to the sides. The KFM6 is designed to combine the imaging accuracy of angled coincident directional microphones with the low-frequency bloom and spaciousness provided by spaced omnis. It also gives excellent out-of-the-head imaging—almost binaural in its effect—when auditioned over headphones. We positioned the Sphere on a Manley Labs Starbird stand just over 8' from the reference point on the front of the piano, dead center between the omnis, but with the capsules a foot lower than those of the omnis.
By themselves, neither of the microphone pairs gave a sound that was true to both the piano's image and its sound character. The spaced omnis gave the same basic sound that you can hear on Concert: a big, forward, full-blooded tonal balance, but with diffuse soundstaging. The Schoeps Sphere on its own gave precise soundstaging (though not as precise as crossed coincident figure-8s or an ORTF pair of cardioids) and a delightfully true midrange and treble. Its bass was too light in weight, however, and while the balance between the direct sound of the piano and the reverberant field in the church was excellent with the mike in the position chosen, the sound was overall a little too "cold."
The outputs of the four microphones were amplified with a solid-state Sonosax preamplifier and recorded in both analog and digital. Cabling was all-Cardas for the Sphere and a mixture of AudioQuest and Beyerdynamic for the omnis. The two-channel analog machines—an Ampex ATR-100 using ½" tape and a ReVox PR-99 using ¼" tape—were the backups; we were fortunate to be able to use a 4-channel open-reel Nagra-D as the main, digital recorder. This superb Swiss machine was reviewed in the January 1996 Stereophile and is capable of storing either two or four channels of up to 24-bit digital data on 5.75" reels of Ampex 467 tape. In two-channel mode, each reel lasts two hours; four data channels give just over an hour's worth of recording time at a 44.1kHz sampling frequency (48kHz is also available).
The A/D converters used were the Nagra's internal 20-bit ones. Although the Nagra-D has conventional-looking peak-level meters—quaintly called "modulometers"—I monitored recording levels with a Dorrough AES/EBU meter. This useful instrument accepts a digital data input and has a 1dB-resolution scale from -1dBFS down to -30dBFS, with -2LSBs, -1LSBs, and 0dBFS indicated by the top three LEDs turning red. It also indicates both the instantaneous peak level and a calculated average level on a continuous basis. I set the levels as high as possible to maximize signal resolution. If you lose resolution at the A/D stage, it's gone forever.