Schoeps KFM-360
A sphere, four capsules, and a processor that turns a room into six channels. The setup is the price of admission.
Overview
The KFM-360 is not a microphone you point. It is an 18cm sphere with two CCM 8L figure-8 capsules that record at an angle of 120 degrees, built for close-miking applications. It ships with a "Y" adapter cable and mounting accessories. It belongs to a small family: the sphere-as-baffle school of stereo and surround capture, where the geometry of the body does the imaging work and the capsules just report what the surface hears. Schoeps lists it at $5,550. That buys the microphone and its accessories, not the box that makes it a surround system.
That box is the DSP-4 KFM 360, a processor listed at $6,305 with built-in AD/DA converters. It turns four capsule signals into six. Pro Audio Review (November 2003, p.28) walked through the whole arrangement and put the complete system at $12,250. It describes the sphere as a 180mm-diameter body carrying two CCM2S omnis plus the two CCM8L figure-eights, one each side facing front and back, with each figure-eight's positive phase facing forward. The same review noted the DSP-4's close physical and functional relationship to Schoeps' Polarflex DSP-4P Microphone Modelling Processor, so anyone who has handled one will find the front panel familiar.
The processing itself is a matrixing job, and the period coverage is clear about what kind. The sphere gives you a stable acoustic baffle, the figure-eights give you the difference signal, and the processor lets you dial in the result after the fact.
What the DSP-4 buys you is post-production leverage. The review was also honest about the cost in ergonomics: the system is complex, and it can be confusing thanks to the double use of the rotary controls and the need to select correctly between the two basic operational modes, "A" and "B." That is not a small caveat. You need to be sure which mode you are in before you trust a take.
The listening reports are the reason people put up with it. Pro Audio Review (November 2003, p.28) found that playback of walkaround test recordings gave front left/right imaging of the kind the reviewer wanted from his own stereo work. The acoustics of the recording room were "transferred" to the playback room, and there was a felt relationship between front and rear reproduction. The review also offered a proviso: with an ITU-style 5.1 monitor layout and its wider-spaced rears, rear movement reads as more distant and the imaging is more diffuse. That suits ambience portrayal, and the reviewer preferred it anyway for the larger sweet spot the wider rear placement affords. The system was also taken to a North London church session for early music by Purcell and Dowland. The DSP-4's analog outputs were fed to an ADAT's unbalanced inputs without trouble, and separate surround versions were cut alongside a conventional stereo recording for comparison.
Collectors and studio people should understand what this is before chasing one. It is a system, and the microphone alone is not the system. The $5,550 sphere without the $6,305 DSP-4 will not deliver the six-channel result the design is built around. The pieces surface separately on the used market, so a buyer needs to decide up front whether they want the complete chain or just the sphere as a stereo and close-miking tool. The complexity that Pro Audio Review called out is also the maintenance story. Rotary controls doing double duty and a mode switch that must be set correctly are the kind of interface that turns into a troubleshooting session if a unit has led a hard life.
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