Category Archives: Stereo Pair

AKG C747 More Than Just A Podium Conference Mic.

AKG C747

First introduced in 1987 the AKG C747 was originally designed for ‘unobtrusive speech applications when mounted on a podium or lectern, or for teleconferencing activities’.  From this somewhat uninspiring start, these days the C747 is widely acknowledged as one of the most versatile microphones AKG ever produced!

Just a glance at the tech spec tells you that this was not a microphone simply doomed to deliver the Chairman’s annual report!

  • Smooth frequency response from 30Hz -18kHz.
  • Rapid transient response produced by tiny, low-mass, capsule.
  • Tight hypercardioid polar pattern, giving excellent separation.
  • SPL rating of 133db.
  • AKG C747 Frequency Response GraphAKG C747 Polar Pattern

It didn’t take engineers long to realise that this neat, pencil sized miniature shotgun microphone has many uses away from the conference hall!

AKG C747 Matched Pair

I recently acquired a well-matched pair of old C747s and it occurred to me that although advertised as having some ‘shotgun’ characteristics, these neat little condensers do in fact behave pretty much the same as any other hypercardioid microphone.  I therefore wondered how they would get on as a crossed stereo pair.  I have seen them occasionally used like that in a conference speech setup, but never recording a large symphony orchestra! (Frequently used as spot mics but certainly not as the main pair!)  So here goes …………

CLICK HERE for Symphony Orchestra sound clip.

The mics were crossed at 65 degrees (at the capsules) and positioned on a tall stand about a metre behind the conductor. N.B. To get the full effect of this recording you need to download it in full resolution and play it on speakers at the sort of volume that will really annoy your neighbours!

AKG C747 Crossed pair at 65 degrees

Here below are the Tech specs for both the AKG C747 and the current model the C747 11.  It is interesting to note that in the C747 11 literature various instrumental applications are also illustrated. (guitar, saxophone, snare, drum) The newer model also has a slightly different frequency response, more tailored towards speech. Either way these are fabulous, unobtrusive, little mics that will blend seamlessly into almost any situation!

C747-manual

AKG_C747_Service_Documentation

AKG_C747V11_Manual

AKG_C747V11_Polar_Patterns

AKG_C747V11_Cutsheet

N.B.  The Hi-Pass filter on these mics is hidden away on the XLR plug (also containing the mic preamp)

AKG C747 Hi-pass filter

 

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Oktava MK-012 Matched Pair. My favourite Stereo Microphone Techniques.

If you are looking for a small diaphragm condenser microphone that will add extra sparkle to your high end, more presence to your mids, and greater weight to your bass………… then the Oktava MK-012 is definitely not for you!! However, if you are looking for an accurate microphone which simply reproduces what it hears, then the Oktava MK-012 is definitely worth considering.

Oktava Mk012 Matched stereo pair.

I bought a matched stereo pair about 10 years ago (direct from Oktava) and they have earned me more money than any other mics I own! I have used them on hundreds of live shows for many different purposes, including drum overheads, hi-hat, Latin percussion, grand piano, acoustic instruments, and as ambient mics. However, it is on classical music recording that they really excel. I have used them in a variety of stereo configurations and in each case they provide a clean accurate account of the performance, capturing the finest nuances of timbre and texture.

Here below are my favourite stereo microphone techniques illustrated with the Oktava Mk-012s  

These microphones have not been ‘modified’ in any way and the recordings linked below have not been EQ’d or processed. Although the streaming quality is reasonably good, for more detailed listening most of the tracks can be downloaded off Soundcloud in their original full resolution wav format.

Near-coincident X-Y crossed pair at 90 degrees gives a phase-coherent stereo image with excellent positionality. The angle between the mics can be altered to suit the width of the subject and the relative distance of the mic placement. Particularly useful for chamber music and small ensembles. Cardioid or hyper-cardioid capsules can be used.

Oktava do now make a dedicated figure of eight capsule. In which case a pair of those would be another option.

CLICK HERE for sound clip of wind quintet.

N.B. The shock mounts are Rycote InVision  INV-7   and (below with piggyback clips)


M-S pair using the Oktava figure of eight adapter which utilises 2 cardioid capsules back to back, in opposite phase. The Mid mic can be cardioid, hyper-cardioid or omni. As with the X-Y array, the M-S pair produce an accurate phase-coherent image. Works exceedingly well on wide subjects such as orchestras and choirs, particularly when the mic position needs to be close to the performers. Has the additional advantage that the relative levels of the mics can be manipulated in post-production. (Reducing the level of the Mid mic and raising the Side channels widens the image. Increasing the Mid and lowering the Sides ends in Mono!)

CLICK HERE for sound clip of male voice choir with brass.


ORTF pair. Cardioid capsules set at 55 degrees and spaced 17 cm apart. Emulating the inter-aural time differences between our ears this configuration produces a detailed but somewhat more diffuse stereo image than the previous examples. This array produces a good sense of depth and perspective. Many engineers argue that ORTF pairs give a more ‘musical’ sound. (?) Excellent for choirs and orchestras.

CLICK HERE for orchestral sound clip


Oktava MK012 Jecklin Disc

The Jecklin Disc takes the principles of the ORTF pair one step further and introduces a foam and fur covered 12”disc between the microphone ‘ears’, emulating the reflective, and shading characteristics of the human head. This array utilises a spaced pair of omni capsules angled slightly outwards. The Jecklin disc with a pair of MK-012s produces a remarkable sense of ‘being there’. Excellent in situations where, along with the performance, you want to capture the acoustics of a great sounding hall or church. Good with subjects of any size and can be positioned at a distance without losing ‘presence’.

CLICK HERE for sound clip of violin concerto

CLICK HERE for sound clip of choral concert

CLICK HERE for sound clip of A Cappella singers in small church

 Anecdote

Some years ago whilst recording a live performance of Monteverdi Vespers, I was somewhat taken aback at the start of the concert by the following occurrence. As the choir processed in from the back of the church, they suddenly started singing!! Arrgh! With almost any other array this would have been a recording disaster. As it was, the pick-up of the Jecklin disc with its MK-012 omnis is pretty much the same from behind! The choir processed down the length of the church and filed past on either side of the mic stand and took their positions in front still singing! Sounded great!


Response graphs

One thing I particularly liked about my MK-012s when they arrived, was the inclusion of individual printouts of the response characteristics of each of the 6 capsules. Below is the printout comparing the matched frequency response of the 2 cardioid capsules, complete with handwritten details!

Oktava MK012 Frequency Plot for individual cardioid capsules.

Tech Spec for Oktava MK012

P.S.

Having provided a neat wooden box it is commendable that Oktava didn’t waste money on fancy, glossy, printing on the packaging! No hype, no bullshit, no celebrity endorsements, just a great sounding pair of mics !

Oktava MK012 Fancy Packaging 2