Life’s the same, moving in stereo” . . . so said the Cars, way back in 1978. And it holds true today: Stereo audio rules the roost (despite surround inroads). But many of us are still capturing mono tracks, or creating stereo using multiple mics. For many situations, a single stereo mic might be a better tool. That’s where Royer’s SF-24 comes in.
The SF-24 is based on Royer’s stereo SF-12 coincident ribbon microphone. It features a pair of figure-8 patterned capsules, positioned one above the other at a 90-degree angle. It uses a thinner (1.8-micron) ribbon than Royer’s popular R-121 and R-122 mics, making it a bit more detailed and sensitive, but at the expense of slightly more fragility. But before you decide the SF-24 is “fragile,” note that it’s still rated to handle sound pressure levels as high as 130dB without problems — impressive for a ribbon. (For a review of the SF-12, see the September ’00 issue. The mono version, the SF-1, was reviewed in March ’02.)
So if the SF-24 is so similar — in fact, identical — to the SF-12, what’s the point? There’s one other detail: The SF-24 is an active ribbon, meaning that it has a built-in preamp, just like a condenser mic. (Almost all other ribbon mics are passive.) The built-in preamp provides one overwhelming benefit (among others, but this is the biggie): It isolates the microphone from the effects of preamp impedance. With a standard ribbon, the preamp has a major effect on the sound and output of the mic. Depending on the impedance, the preamp may not have enough gain to amplify the mic properly, or may add noise to the signal. With the SF-24 (like Royer’s R-122 before it), these problems evaporate. The mic/preamp interface becomes transparent, and the output of the mic remains stable and clean regardless of preamp impedance.
Cool, so you can plug the SF-24 into almost any preamp. Doesn’t matter if the mic doesn’t cut it sonically. Fortunately, the SF-24 shines in a variety of applications. On drum overheads, it has an open smooth sound. It’s not hyped like many condensers, but sounds “natural.” The SF-24 takes EQ nicely, without becoming harsh — a touch of 10k and a slight 300–400Hz cut resulted in a killer stereo drum sound.
The SF-24 was an excellent match for percussion in general. It rounds out hard transients in a pleasing way. On congas, for example, the SF-24 provided exactly the sound you’d want to hear for a recording.
Nylon-string guitar proved a perfect match for the SF-24; the mic is clean enough to handle high gain without adding noise. It has less proximity effect than other ribbons, so you can get in close without excess boom.
Woodwinds and French horn also worked well. These instruments can have annoying mids on certain notes, but the SF-24 translated them as nicely balanced. Trumpet and brass sounded fine, although the mic gave up on screaming high notes when placed five feet away.
Using the SF-24 on piano resulted in a wonderful stereo image, but required a lot of EQ to get the pizzazz — air and brightness — we were looking for. A string section recorded at Oceanway in Nashville sounded lush and broad — the stereo image was great. There was a slight lack of top and bottom, but the overall result was excellent.
The SF-24 is relatively compact and visually unobtrusive, although you’ll still want a sturdy mic stand supporting it. The shockmount holds the mic well, but requires a firm shove to insert the mic. If the mic is inserted incorrectly, it’s difficult to get out of the mount.
The SF-24’s active preamp provides a huge benefit, removing impedance from consideration when choosing a preamp. The mic itself does a great job of capturing almost any source. The stereo image is excellent, the tonality is pleasing, proximity effect is controlled, noise is low, and versatility is high. Because it handles transients so nicely, the SF-24 is a great tool for digital recordings, providing a round, harshness-free midrange.
It’s pricey at $3,795, but considering you’re getting two mics in a stereo arrangement for the price, the value works out. For stereo recordings, the SF-24 has the goods.