Austrian Audio were born out of AKG but how much of that classic studio microphone DNA has found its way into their OC series microphones? In this extended on test article we try the Austrian Audio OC 818 and 18 condenser microphones on a variety of sources. We find a lot of Austrian-built microphone for surprisingly little money.

New mic companies aren’t rare. Boutique manufacturers come along fairly regularly. More often than not they are offering a replica or a new take on a classic vintage design which is no longer available. This is a good thing, particularly when really good replicas come along. When I first heard about Austrian Audio I was intrigued because in spite of the story of this company’s creation, they were clearly interested in creating new products from scratch. It was a long wait, I first contacted the company before they had any products announced, but having spent some time with their first mics, the OC818 and its little sibling the OC18, I’m glad to report that there is plenty that is new left to be done in the world of conventional analogue microphones and if these are anything to go by I can’t wait to see what’s coming next!

Austrian Audio were formed when AKG announced they were closing their Vienna site, the historical home of AKG. The team were to be disbanded and in a rare example of a happy alternative ending to this too familiar storyline, a new company was born out of a management buyout, keeping microphone manufacturing alive in this historic location and a team of engineers who between them are estimated to have a combined experience of 300 years!

So we have the potentially perfect situation of a company with the agility of a startup and the experience of an established name. I was very interested to see what came out of Vienna!

After a significant period of development Austrian Audio have released a range of two microphones and two pairs of headphones which we hope to try very soon. The microphones are both large diaphragm condensers. the OC818 is a multipattern design, the OC18 is a fixed cardioid model.

The OC (Open Capsule) series is clearly the result of a carefully thought through design brief. Austrian Audio set out to design a mic which prioritised the capsule. Make the best capsule you can and convey the signal captured by that capsule without further colouration. As a result this is a transformerless design with best in class self-noise and the basket itself is deliberately large to minimise colouration caused by internal reflections, in fact internally the bottom of the basket space contains a diffuser similar to those found in the walls of studios to break up internal reflections in the basket.

The CKR12 Capsule

The most coveted mics from the AKG back catalogue all have one thing in common, the famous CK12 “Brass” capsule from the 50’s and 60’s. This capsule is found in the C12, the ELAM 251 and the early (read “desirable”) C414s. As great as it may have sounded, this capsule was complex, costly and had a high rejection rate in the factory. It performed well but didn’t lend itself to mass production. At a time when laser measurement wasn’t available, the electrodes had to be machined very precisely, down to micrometer accuracy. The tensioning of the diaphragm had to be extremely even over the whole surface and the brass rings which gave the capsule its unofficial name, while usefully heavy, had to be held in place by 12 tensioning screws per side. On a bad day only 2 or 3 capsules would leave the production line per day!

Austrian Audio put a lot of work into designing their new CKR12 capsule which performs like the CK12, particularly at the the top end where a good CK12 is noted for its smoothness, but designed a capsule which is consistently manufacturable. AKG moved away from using brass to plastic in later versions of their capsules but, while these were more manufacturable, they seemed to lose something in their performance.

The answer Austrian Audio arrived at was to design a capsule which used ceramic in place of brass. Being a more suitable material and having a relatively high mass it solved the manufacturing issues without compromising the sound. This patented ceramic design has the advantages of brass but is stable, doesn’t corrode and is an electrical insulator, improving performance when moisture might cause issues in a brass capsule when bringing a cold mic into a warm studio.

The OC Microphones

Physically both the OC818 and the OC18 are very similar, the OC818 has an attractive finish which I’ll call “off gold”. The OC18 is black. It’s a simple design and physically quite large. The OC818 has three sliding switches arranged on two rows, the top switch is a 5 position pattern selector. Both 818 and the 18 have a 4 position HPF and a 3 position pad.

The HPF settings are interesting in that the 40 and 80Hz positions engage 12dB/Oct filters but the 160Hz setting engages a filter which is a 6dB/Oct filter from 160Hz and 12dB/Oct from 80Hz. The Pad switch has -10 and -20dB settings and with its transformerless design the mic can tolerate levels up to a dizzying 158dBSPL. In applications where you might need this the old advice of using your ear to find the right mic position isn’t recommended…

It’s the polar pattern switch which hints towards some of the interesting tricks the OC818 has up its sleeve. A 5 way switch has omni, fig 8 and hypercardioid as expected but the cardioid position has forward and backwards facing cardioid patterns printed and the 5th position looks like a filled in circle? The back of the 818 features a grey rubber captive bung which plugs a mini XLRM socket. This allows the output of the rear facing diaphragm to be captured independently of the front. This is what the second cardioid legend was referring to on the switch and anyone who understands how a multipattern microphone works will recognise the possibilities this presents.

PolarDesigner

A multipattern microphone works by combining the output of the rear facing diaphragm with the output of the forward facing diaphragm. It is the fact that multipatterm mics have two diaphragms and single patterm mics only have one which makes them more expensive. You can try this yourself if you have two cardioid mics. Just set them as close as you can to each other, one facing forward, the other facing backwards and route their outputs to a pair of mixer channels. By varying the level of the rearward facing mic you’ll get everything between cardioid (rearward facing mic off) to omni (rearward facing mic at same level as the forward facing mic). Of course these two mics won’t be coincident in space so the patterns will fall apart as frequency rises and the distance between the two mics becomes more significant compared to the wavelength but it’s a surprisingly effective experiment.

Of course in a dual diaphragm mic the two diaphragms are as close as is it possible to be so the patterns behave properly. The significance of having access to the signal from both diaphragms is that rather than having to choose your polar pattern at the mic and having it “baked in” to the signal recorded, you can record both outputs and choose your polar pattern later.

This brings me to one of the most interesting features of the OC818, the free Polar Designer plug-in. This plug-in allows detailed manipulation and even automation of the OC818 polar response. By mixing the levels of the two diaphragms the polar pattern can be varied from forward facing cardioid, through hyper cardioid, fig 8, omni and through to rear facing patterns. It gets more sophisticated though as the inclusion of up to 5 frequency bands with phase linear crossovers between them allows continuously variable polar patterns to be set for each band. This allows bespoke polar responses to be dialled in pre or post record so spill can be minimised or unhelpful frequencies reduced on a per-band basis.

Setting these bands can be done manually and with care excellent results can be obtained when you want to exclude unwanted spill which is particularly prominent in a specific part of the frequency spectrum. However there is an automated setting in the plug-in in which you can play just the spill to be excluded, or the wanted sound and the plug-in will set up the most favourable combination of patterns and crossover frequencies to exclude or include sounds or to find the best compromise between inclusion and exclusion. In tests with a singing acoustic guitarist, really useful amounts of spill reduction could be achieved, though it is important not to compromise the wanted sound while trying to control spill. Luckily manual tweaking of the settings is always possible.

Bluetooth And Presets

Although I didn’t have one to try, there is an option of using the optional OCR8 Bluetooth dongle which when used in combination with the free PolarPilot App allows remote control of the biasing voltages which control the polar pattern. The possibility of remote control of mics during tracking is very appealing, recording the output of the second diaphragm allows such decisions to be put off until the mixing stage but to capture the second output does require an additional cable, preamp and track.

Being able to audition different polar patterns from the control room is very appealing and not all mics are easily accessible during a tracking session. The final position on the polar pattern selector, the filled in circle setting, is available to store a custom polar setting accessible without the OCR8 attached. If you want a particular polar pattern which falls between cardioid, fig 8, hypercardioid and omni you can set it up as your preset for easy access.

Accessories

The OC818 Studio Set arrives in a smart, and pleasingly slim aluminium case. The mic is provided with a foam windshield, cable adapter for the second diaphragm output socket, a regular mic clip and a shockmount. The mounting options are both a case for praise and criticism. The shockmount is great quality. Thankfully Austrian Audio haven’t continued AKG’s shockmount heritage as the shockmount provided with the C414 is something if which I have a longstanding hatred. Thankfully this shockmount is sturdy and secure, I would happily trust it to keep hold of my precious mic at the most precarious of angles and not to snap into pieces when transported in the same case as a loose DI box. Unfortunately there are a couple of things I’m less keen about. One is that because the shockmount holds the body of the mic, rather than just the connector shaft, it’s not possible to rotate the mic in the shockmount. Awkward when you have to move the mic stand to rotate the mic. The other criticism is that the output from the rear capsule can’t be accessed with the mic in the shockmount. A way around this is to mount the mic backwards, that way the adaptor cable can exit the shockmount to the front but the front/rear capsules are reversed. It’s perfectly functional but I wonder whether a mark 2 version of the shockmount might be in order?

The OC18 doesn’t suffer the second output problem because it doesn’t have this feature. The Studio Set for the OC18 is the same as for the OC818 apart from the omission of the cable adapter.

How Do They Sound?

In a word, great. There isn’t anything immediately attention-grabbing about their performance but after a few minutes getting used to their sound, when you return to something else you’re struck by the openness of the top end on the OC mics and the lack of midrange clutter. There’s little meaningful to be learned auditioning them against budget condensers, if you are used to the sound of a typical inexpensive LDC you’ll definitely notice the smooth, non-fatiguing top end. Test recordings of an acoustic guitar and voice proved these to be classy performers.

Usually when presented with a cardioid only mic and a multipattern mic, I’ll favour Mid/Side recording as it is inherently symmetrical and therefore more suitable for non-matched pairs of mics. However the consistency of manufacturing means that an OC18 and an OC818 can be used for stereo applications using cardioid patterns. The drum overheads recording below was captured using a spaced pair and the precision of the stereo image is impressive, you can hear exactly by how much the kick and snare are off to the left and you can almost see the crash cymbal move as it’s hit.

Clean and balanced are words which come to mind and while in the list of possible adjectives which could be used to describe a microphone these words might sound boring, the results are far from that. What these mics are is versatile. They work on everything I tried them on and I see no reason to suspect they wouldn’t work just as well on anything else. Something which can’t be said of character mics.

As an experiment I tried the OC18 against a TLM103 with a spoken word test. The differences were striking. The TLM103, criticised by some for sounding uninteresting, is superficially similar: A high quality, transformerless, cardioid-only, large diaphragm condenser. The results were striking in just how different they sounded, with the Neumann sounding positively coloured compared to the OC18. The Neumann’s mid-forward character and upper midrange sizzle being notably absent from the OC18. But the OC 18 had a sweetness to the top end which was beyond the TLM103.

While recording singer-songwriter Jack Kessel at Cube Recording in Cornwall, the temptation was too much not to grab a pair of C414XLS and put them up on the acoustic guitar alongside the OC818 and 18. While the OC818 isn’t and shouldn’t be thought of as any kind of “new 414” - It probably owes more to the C12 than it does to the 414. It’s a mic which I would think of as a natural alternative to the 414 and basically we wanted to so we did it! The results were surprising. The 414s sounding tubby and veiled by comparison. As the methodology wasn’t rigorous enough to be called a fair test I won’t publish the files, the mic positions weren’t matched as closely as they might have been and our listening wasn’t blind, let alone double-blind but anecdotally I’m convinced that these mics would be my choice every time.

Audio Examples Recorded At Cube Recording

Gareth Young, the owner of Cube was taken by the OC818 and 18. So much so that he held on to them after the session and has been using them as his go to for drum overheads and acoustic guitars since then. He said that while they have AKGs and Neumanns he found he was coming back to the Austrian Audio mics because of their clarity. When the demo pair go he’s thinking very seriously about buying his own pair.

Conclusion

The OC818 is about $1,099 and the OC18 is about $749, so if you want some sensibly priced, Austrian built, large diaphragm condensers, particularly if you are looking for your first set of “proper” mics. Ones which will stay with you for decades and which you won’t outgrow, these should be at the very top of your list. I’ve always admired the Audio Technica 4050 as a clean, flexible, do anything microphone. These are like that but courtesy of the Polar designer plug-in and dual outputs, more flexible and probably nicer sounding. I no longer have a pair with which to compare them. If you need something for drum overheads, stereo recordings of strings, brass or choirs, pianos, acoustic or electric guitars, vocals, I could go on but basically anything you might need to record, these will be every bit as good as anything else you might try but crucially they will never be the wrong choice. There might be a better choice for a particular instrument but you’ll never find you have the wrong mic with these.