rankfurter Allgemeine Zeitung  10 April 2001

Good Sound on a Smart Head

A walkman microphone with excellent acoustics at an affordable price

Nobody notices a thing.  It just seems as though a walkman enthusiast is strolling through Frankfurt’s inner city with a head piece in each ear.  Not even in St.Paul’s Church does the ear adornment and cable seem out of place.  However, behind the small blue button in the left ear and the red one in the right ear lies a little secret.  What you see is not exactly a walkman head piece, but a high quality electret condensator microphone.  With this apparatus it is possible to make live recordings not only very inconspicuously, but also of an astoundingly high quality.

Soundman offers the Originalkopfmikrofon  (OKM) in several designs.  Enclosed in a stable wooden case, redound in red cloth, the goods can be bought at a price range from 137 to 270 euros.  The bottom of the range OKM I takes from 30 Hertz to 16 Kilohertz, at a gauge difference between the two microphones that amounts to, at its highest, 1.5 Decibels.  The somewhat better OKM II costs 195 euros, reaching up to 20 Kilohertz at a gauge difference of less than 1 Decibel.  For the more demanding requirements, there is the Studioversion (270 euros).  The channels deviate from each other by up to 0.5 Decibels and the frequency response is extremely even.  At the end of manufacturing, a computer automatically picks out the matching microphones.  A special R-version for rock music costs 246 euros (as a Sudioversion 310 euros), and tolerates a higher acoustic pressure, which is necessary not only for rock and pop, but also for trumpet sounds.  We have tried out the OKM II in its Studioversion, which is the model used by the Westdeutschen Rundfunk and the BBC.

The OKM’s small electret capsule is attached to a metre long cord, with a coil protecting the cable.  The stereo jack on the other end is gold plated.  It is possible to use all data media when recording with the OKM.  Naturally, a particularly sensible is option is a digital form of storage, such as DAT, or the robust and compact mini-disc (MD), that almost matches the CD for quality of sound and is almost always the best choice.  If the recorder plug in power for energy saving microphone bushing is not offered, an extra current entrance is required.  Soundman recommends the Adapter A3.  In addition, the thumb sized adapter offers a subsonic noise filter and adjustable buffering (minus 20 decibels) for loud recordings.  However, the most interesting aspect of the A3 is the possibility to use it with the line input of the recorder.   Through this, it is possible to gain a microphone voltage that is 30 decibels higher which is a considerable gain vis-à-vis a direct connection to a conventional input.  In practice, use of the small button microphones is an uncomplicated affair.  Although they do not sit particularly comfortably in the ear, they nonetheless hold firmly in position.   Because of the protected placement, the majority of obtrusive sounds that are associated with tie attached microphones (for instance scratching due to friction) is bypassed.  The ears also offer a degree of protection from wind interference.

Given all of this, it is no surprise that the OKM’s acoustics are outstanding.  The mini disc recordings utterly inspire.  One should note that during manual modulation room for readjustment should still be allowed.  That makes sense and is important because temporary surges of the maximum signal gage leads to unpleasant contortions.  Both microphones have spherical traits.  Of course, this binaural stereophonic sounds the best when replayed using a head set on a real head.  Yet, in the case that one may want to leave her head free for other uses, Soundman has an interesting deal to offer.  For 248 euros provide a dummy head with the same geometry as the AKG D 99 C.

All things considered, the new Soundman microphones are highly recommended.  This may include instances where a music enthusiast wants to record their own chorus or a cameraman wants to improve the tone quality for their camcorder.


Das Dia-Magazin

Issue 4/1993

Test Report:

There are some things that are simply too good to be true.  And there are some things that are simply too inconspicuous to have their true grandeur immediately recognized.  One such thing is the SOUNDMAN OKM II, an Original Head Microphone that makes breathtaking stereo recordings.

At first glance, it would be easy to dismiss this as your common 08/15 headphone. But only at first glance.  In a plastic box that is barely palm sized, one finds a microphone that resembles ear plugs.

I tested it with a Sony WM-D6C walkman.  Its operation is quite simple.  The red plug goes into the right ear, the blue one into the left, the mini-latch into the mike-bush and then, just record.  I found the playback through the headphones simply thrilling – an acoustic ear feast!  What’s more, the quality through the speakers is first-rate, with the room effect not being so pronounced.

A ‘solder piece with power supply and additional A3’ is delivered with the OKM-II. This supplies the Elekret condensator microphone with voltage when the audio supply is short.  This also allows the OKM-II to be applied to DAT-Portables particularly well.

The operation of the OKM-II with the A3 adapter through a Line-input contains additional subtleties.  A subsonic noise filter balances the close speaking effect and attenuates the irrelevant frequencies below 300Hz. It also provides further damping for loud sound sources (-20dB).

The times when one had to lug chunky microphones around to bring home O-tones for a slide show seem like a long-gone era of the past.  The OKM is small and inconspicuous, and is currently offered for less than 300DM.

I hope that this filigree device lasts long and never breaks down on me – I can’t do without it any more.



By Karen Stackpole

Electronic Musician, Jan 1, 2002

If you’ve ever wanted to be a dummy head for three-dimensional recording, here’s your big chance. The OKM II K Classic Studio Binaural Stereo Headset microphone ($325), from German manufacturer Soundman, is one model in a series of in-ear mic pairs designed primarily for binaural recording. The headset is simple and inconspicuous and looks a lot like ear-bud stereo headphones. The mics are intended for use with compact recording devices that have ⅛-inch stereo input jacks, such as MiniDisc recorders and DATman-style devices.

Package Deal

The OKM II K Classic Studio mics are a computer-matched pair of tiny omnidirectional, electret-condenser elements. The capsules are embedded in molded-plastic ear buds that look like miniature yo-yos with six prongs jutting outward on each half. Although they are visually reminiscent of torture devices from the Spanish Inquisition (who expected that?), the prongs accommodate and effectively secure a set of foam screens to protect the capsules and your ears. The headset comes nestled in a black plastic case that incorporates a spooling device for the slim mic cable to safeguard against tangling and damage. An extra set of foam screens is included.

The headset includes an A3 adapter, which supplies DC power to the electret elements. The A3 purportedly offers increased dynamic range and quieter operation over directly plugging the mics in to the ⅛-inch mic jack on a portable recording device. The adapter is housed in black plastic and runs on a 6V battery. The battery is supposed to last 100 hours, and a battery check button activates an LED indicator to let you know if power is low. Features include a switchable -20 dB attenuation pad and a selectable low-cut filter.

The OKM II K headset and accessories come in a black wooden box and fit snugly into a formed plastic tray coated with a red velvety covering. The lid is lined with foam and is also dressed in red velvet, which gives the package a classy look. It also includes an owner’s manual and a demo CD offering an introduction to various uses.

Testing 1, 2

I took the mics to a number of live recording gigs and conducted a few controlled tests. I don’t own a MiniDisc recorder, so I made a custom cable to use the mics with a portable Sony TCD-10 Pro DAT machine and a Panasonic SV-3800 DAT machine.

For the live tests, I recorded several bands in small- to medium-size venues, with and without sound reinforcement, all with a variety of instrumentation. In addition to playing the dummy-head role, I recommend placing the mics ¼ inch apart on a flat surface to serve as boundary-layer microphones.

For the controlled tests, I binaurally recorded a drum set (from the player’s perspective) and compared that with my usual technique of using overhead cardioid condensers in an XY configuration. I also recorded acoustic guitars with the OKM II K in a boundary-layer arrangement and checked out the A3 adapter’s -20 dB pad and low-cut filter. Because the setup was so portable, I couldn’t resist using the mics to record ambient sounds and effects while walking around too.

Listen to This

The OKM II K reproduced the original listening experience fairly well, especially when listening back on headphones. Any time I moved my head to check levels, however, the stereo image shifted. When you wear the mics while recording, think “mannequin.” The microphones captured ambient sounds quite well with minimum hassle. Although the recordings weren’t on par with audiophile levels, they were quite good.

The OKM II K mics don’t sound very transparent, but they have a punchy low end with good presence. The highs are a bit gritty and biting, and the upper mids sound slightly distorted. Midrange frequencies between 250 Hz and 500 Hz are lacking; although that characteristic reduces warmth, it makes some rooms sound less boxy. On sources such as baritone sax and upright bass, the mics sound a little thin. Compared with the Oktava MC012s as drum overheads, the binaural mics represent a more dramatic spatial image, but transients are less clear and the sound isn’t as full. Nonetheless, the recorded results sound realistic enough.

The microphones are small and low profile. After years of toting around a loaded rack, mic stands, and a case full of microphones and accessories for stereo recordings, using the OKM II K gave me an immediate sense of emancipation. The Soundman OKM II K Classic Studio Binaural Stereo Headset microphone is an excellent low-profile option to make club recordings and to collect sounds in the field, but it’s not exactly professional quality. At the price, however, the mics make an affordable and handy addition to anyone’s low-pressure recording arsenal. Even when you consider its limitations, the OKM II K headset is a bargain for convenience and decent sound quality. If you need to be stealthy while recording, the mics are a fine choice.