Neumann’s Series 180 Mics (L-R): the KM 184, KM 185 and KM 183

All three of the new mics are based on KM100 circuitry and are 48-volt phantom powered, although a new DC-to-DC converter changes the 48 to 60 volts and provides a more stable polarizing voltage. A side benefit is that the mic’s transformerless output is more forgiving of the unbalanced inputs of consumer gear.

The KM 183 has a boost of approximately 7 dB at 10 kHz in the free field but a flat frequency response in the diffuse sound field. Just like the KM140 microphone, the KM 184’s response starts to lift at 9 kHz, which means that the new KM 184 is brighter than the original KM84. This characteristic has been achieved by slightly modifying the capsule’s rear opening, rather than by electronic means. Compared to the KM84, the KM 184’s dynamic range is increased by 21 dB, self-noise is reduced to 25 dB (CCIR), and the new mic can handle SPLs up to 138 dB.

The KM 185 hypercardioid features a 10dB front-to-back-to-side rejection—minimum sensitivity is at 120° off-axis. The pressure gradient transducers in both KM 184 and KM 185 provide for smooth frequency responses, not only for the on-axis sound, but also for off-axis sounds.

LET THERE BE DRUMS
The 180 Series mics’ small size makes them perfect for miking acoustic and string instruments, or getting in and around a drum kit. I have always favored close-miking drums with condensers for light-to-moderate playing—I find that condensers pick up more of the subtleties of a drummer’s technique—although they may not be the best choice for bashers. For this Field Test, I used two KM183s for overheads (one over the ride cymbal/floor tom side and the other over the snare/hi-hat side), a KM 184 for the snare drum close mic and the KM 185 for the hi-hat.

The drum recording room was small, and I found the omnidirectional overhead mics picked up a lot of reflections from the wood paneling and floors, positively influencing the instruments’ tonality. The mics ended up being about two feet above the highest cymbal, but even this close, the omnis captured more of the room sound than the pair of cardioids I normally use. To get a little drier sound, I just moved the overheads closer in six-inch increments and reduced mic input gain. A nice feature of omnis, of course, is that there is no change in the proximity effect when close-miking.

I did have to experiment with the lateral spacing of the overheads, as I heard some phasiness when I first placed them about four feet apart. Moving them closer together solved the phase problem, but I have to admit I did like the extra wide sound when they were farther apart.

I placed the KM 184 cardioid close in on the snare drum, where it provided plenty of sparkle, obviating the need for high-frequency EQ, although I did add a couple dB of boost at around 3 kHz to fit the song. If there was ever a place to test a condenser mic, two inches from a rock snare drum is it! The KM 184 had absolutely no trouble at all, even when my flailing drummer tagged the mic’s body right on the Neumann logo. Aside from a loud crack on that particular backbeat, the mic kept on working. I also A/B’d the track before and after the accident and noticed no sonic differences, nor any change in the waveform (scrutiny made possible by Pro Tools). I also noticed that none of the mics got “soft” after hours of use.

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Reprinted with permission from Mix Magazine, August, 2000
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