Thursday, July 17th, 2008 | by Michael Joly
[Editor's note: I am psyched to introduce RecordingHacks' new guest author, Michael Joly! You know his mods, his knowledgeable and calming presence in the audio forums, and his new line of "Michael Joly Editions" microphones. He has been a friend to this project since the beginning, and will be periodically sharing his unique perspective and expertise in this space. Wecome, Michael!]
As a retailer and modifier of Oktava microphones, I’ve studied hundreds of frequency response graphs for Oktava’s small and large diaphragm capsules. This comparative analysis, coupled with listening tests, have provided some general impressions of each capsule type available for the MK-012 bodies.
The cardioid capsule is the most commonly used capsule for the MK-012 body. Unlike many modern small diameter condenser microphones with very bright top end response, the ‘012 cardioid features an essentially flat (±2dB) response from 100Hz to 15 kHz. For this reason, the spectral response of the MK-012 cardioid is likened more often to the venerable Neumann KM-84 than to its brighter successor, the KM-184.
The MK-012 cardioid capsule offers a smooth frequency response out to 90° off-axis, accompanied by approximately 16dB of attenuation at that source incidence angle. Its 180° response offers up to 50dB of attenuation in the 500-1000Hz band, cancellation of 20dB in the bass, and of 40dB in the treble range.
Overall, the MK-012 cardioid can be considered a small diaphragm capsule with flat on-axis response, slightly bright 90° response and warm / scooped 180° ambient response.
Applications: The MK-012 with cardioid capsule is a world-wide favorite mic for acoustic guitar and drum overhead use. Detail, clarity and depth without edginess or excessive high frequency boost.
With substantial 90° off-axis attenuation, flat midrange and slightly attenuated bass and treble, this capsule is a favorite with film and video sound recordists world wide. The ‘012 hypercardioid is essentially flat (±2dB) from 200Hz to 8 kHz, with a gentle 3dB/octave roll-off beyond these points.
90° attenuation is typically 26dB through most of the frequency range, but decreases to approximately 10db in the top octave. The 180° response, by way of contrast, offers about 30dB of attenuation through most of the frequency range but then increases to nearly 50dB in the top octave.
Overall, the MK-012 hypercardioid capsule offers flat on-axis sound with slightly attenuated top and bottom. Its 90° sound is bright, while its 180° sound is warm.
Applications: In addition to its ubiquitous use as a film and video dialog mic, the MK-012 with hypercardioid capsule is a welcome addition to a music recording studio’s locker as well. A pair of these mics would make an excellent choice for drum OH applications where the recordist wants to focus on the kit, minimize room sound and soften the cymbals a touch. The hypercardioid capsule comes in handy during sessions with singing acoustic guitarists, because additional separation between the talent’s voice and guitar can be achieved.
The ‘012 omni offers a slightly brighter on-axis sound than the ‘012 cardioid or hypercardioid capsules. This capsule is essentially flat (±2dB) from 30Hz to 5 kHz, then offers a slight presence peak of 4dB in the top octaves.
Off-axis frequency response mirrors the on-axis sound up to approximately 5 kHz, where both 90° and 180° response curves attenuate at 12dB / octave. Consequently, the ‘012 omni capsule offers slightly brighter than flat on-axis sound with somewhat attenuated HF as the source incidence angle moves to 90° or beyond.
And of course, the omni ‘012 is free from proximity effect, and thus allows very close-to-source placement without bass boom.
Applications: Prized for its natural sound, the MK-012 with omnidirectional capsule is often used for spaced-omni recording of classical or jazz ensembles. And though it might seem counter-intuitive, the ‘012 omni can frequently be used in live sound reinforcement applications on acoustic guitar. Without proximity effect, the mic can be placed extremely close to the guitar (or other soloist instrument) to achieve very high gain-before-feedback.
The MK-101 large diaphragm capsule was introduced in 2004 as a transition from the earlier MK-219 and MK-319 models. The ‘101 shares the same 26mm (active diaphragm area) capsule as the MK-219 & MK-319, much loved for its classic midrange presence and sibilance-free top end. When coupled to the transformerless ‘012 body, the MK-101 capsule offers slightly less body but a bit more clarity than its 219/319 predecessors.
The MK-101 headbasket features a large open area “forehead” for smooth off-axis response in the vertical as well as horizontal planes. Vertical asymmetry of the headbasket allows the recordist to explore different polar responses when using the mic upright or inverted. The small headbasket and body size make for easy placement and minimal reflection between sound source and microphone body.
On-axis: The MK-101 offers a powerful midrange presence and natural top end response with excellent rejection of sibilance.
Off-axis: The MK-101 has moderate attenuation at 90°, giving the mic a wide cardioid pick-up pattern. Its 180° response has a warm spectral balance with strongest output below 200Hz and smooth amplitude reduction to 3 kHz. A moderate high frequency peak lends the overall 180° sound a somewhat warm/scooped spectral balance.
Applications: Like the MK-219 and MK-319 (which use the same capsule), the MK-101 makes a great male or female vocal mic where the recordist needs minimum sibilance but a clear midrange presence. In fact, the ‘101 head driving the transformerless ‘012 body actually reveals some undiscovered “air” this capsule is capable of hearing. I’ve received a number of reports of clients using this mic for drum OH too — large diaphragm “size,” but with the transient response and clarity of the transformerless circuit.
Introduced in 2005, the MK-102 large diaphragm capsule features a small physical profile and flat, extended frequency response — qualities not typically found together in large diaphragm mics. The ‘102 features a 5 micron, 27.5 mm (active diameter) diaphragm and all-brass backplate construction, precision-drilled pattern control holes for classic LDC microphone presence on vocals or instruments.
A close-fitting housing surrounds the capsule and allows the front diaphragm to function with minimal headbasket coloration. In addition, the MK-102’s unique capsule and body orientation reduces reflections between the microphone and the sound source. The MK-102 body disappears completely behind the capsule head when the mic is aimed at the sound source. This leaves only the capsule diaphragm exposed to the sound source for minimal reflections and clear-sounding recordings.
On-axis: The MK-102 offers a smooth midrange and a top end tailored with “presence” and “air” peaks but free from the harsh, excessively bright sound found in many modern LDC microphones.
Off-axis: Frequency response from 90° through 180° closely resembles the on-axis sound and the attenuation of sound over this angular range is exceptionally smooth.
Applications: A lovely female vocal mic with airy qualities perfect for a lighter pop vocal session. A clean and bright top end lends this mic small diaphragm-like qualities for stringed instrument use as well.
Released in October 2006, the MK-103 is a mid-sized (19.5mm active area) diaphragm capsule developed to complement Oktava small- and large diaphragm condenser mics. It provides a useful gradation in time domain response between the small and large diagram sizes, very flat frequency response, and excellent cardioid pattern attenuation over a broad frequency range. The ‘103 provides most of the quick transient response reminiscent of the acclaimed MK-012 small diaphragm mic, but retains some of the magic associated with Oktava’s large diaphragm capsules.
The MK-103 capsule features a tight-fitting headbasket that surrounds the capsule closely to eliminate sources of sound reflections typically found in LDC microphone headbaskets. In fact, the headbasket of the ‘103 has been acoustically designed as an optimally-curved housing to eliminate sharp edge refractions that impart coloration to off-axis sound.
On-axis: Quick transient response and extended high frequency response are hallmarks of the MK-103 capsule.
Off-axis: Moderately strong attenuation at 90° creates a tightly focused cardioid pattern, while very strong midrange attenuation at 180° minimizes room sound and unwanted sound source pick-up.
Applications: The very flat frequency response mid-sized diaphragm mic provides the natural timbre response sought after in small diaphragm mics, but with excellent off-axis rejection and a bit more of the “heft” associated with LDC mics. An Australian client wrote to tell me he’s getting the best OH drum sounds of his career with a pair of ‘103s.
Released in November, 2006 the MK-104 features a completely new 27mm large diaphragm capsule, showcasing a new arrangement and sizing of precision-drilled backplate holes designed to create a “lean and bright” sound without being screechy, sizzly or scooped.
The groundbreaking MK-104 headbasket design features four acoustically-optimized vents that dramatically reduce reflections, smoothing the upper midrange response and improving transient response detail. The MK-104 is capable of rendering high frequency transient sounds with accuracy and detail reminiscent of a small diaphragm mic — but offers the flattering qualities of a large diaphragm condenser.
On-axis: The MK-104 exhibits a smooth and gentle upward tilt from bass to treble that provides several dB more treble output relative to the bass end.
Off-axis: The MK-104 has a unique and useful polar response — at 90° if offers strong rejection of high frequency sound, but at 180° offers a bright spectral response.
The MK-104 capsule excels where the recordist wants an accurate on-axis large diaphragm cardioid sound, excellent transient response and bright room ambience while minimizing HF leakage from adjacent instruments.
Applications: A lean bottom end and rising mid-to-high end response makes this mic a suitable choice when the recordist wants to attenuate bass and accentuate top end. I have one male vocalist client with a very light, falsetto-like voice; he loves the way the ‘104 can be worked very close to reveal intimate detail without adding a lot of bass that would make his voice sound unnatural. This capsule would also be a great choice for drum OH where a sizzly top end and minimum amount of kick drum is desired.
RED R12 Large diaphragm capsule
No longer in production but available in the used marketplace, the RED R12 large diaphragm capsule provides a “midrange scooped” sound in contrast to the classic “midrange forward” Oktava voicing. A fairly high amplitude and broad proximity effect give this mic a huge bottom end sound when used close. A welcome change from many low cost Chinese-capsule equipped microphones, the R12’s high frequency response is fairly smooth and free from stridency.
Applications: A good choice for backing vocal tracks. The slightly scooped response causes backing vocals to recede a bit and stay out of the way of the lead vocal.
RTT M1 and M3 capsule
Impeccable industrial design and machining make the RTT M1 and M3 a joy to see, hold and use. Often specified as a “33mm capsule,” this dimension refers to the outer diameter of the brass backplate. The active diaphragm area measures approximately 28mm. The M1 and M3 capsules are both somewhat lean in the bass (though proximity effect is very usable with a natural-sound boost) with a crisp and clean top end free from sibilance.
Applications: These have a presence almost like a U87 but without the “honk” and are somewhat lean in the bottom. Rob Schnapf (Beck, Eliot Smith), an OktavaMod client, is getting great piano sounds with them.
[Editor's note — needless to say, Michael has already opened up most of these capsules and performed classic OktavaMod upgrades to them. If you're looking for something a little extra-special for your MK-012 body, I suspect Michael might entertain inquiries...]