Austrian Audio OD505

Austrian Audio turn their attention from studio to stage, with an intriguing new vocal mic aimed at live performance.

Austrian Audio are by now a familiar name in studio circles, thanks to their impressive OC‑series microphones and Hi‑X headphones, and their next target is the world of live sound, with two new microphones designed for stage vocal use. The OC707 and OD505 share a similar physical housing, which incorporates an interesting innovation called Open Acoustics Design, but whereas the former employs the same small‑diaphragm capacitor capsule used in the CC8 studio mic, the OD505 uses a newly developed and rather unusual moving‑coil dynamic element.

Several things mark this out as being out of the ordinary. One is that the OD505 is an active microphone, requiring 48V phantom power and delivering a somewhat hotter output than most passive mics; at 4.4mV/Pa, its sensitivity falls somewhere between what’s typical of moving‑coil and capacitor designs. Another is that it also features an innovative cone‑shaped pop filter called the 3D Pop Noise Diffuser. And yet another is the use of a second, rear‑facing capsule positioned directly behind the first.

Dual capsules have been used in quite a few mics over the years, and for several different reasons. In AKG’s classic D224 and its relatives, for example, the two capsules separately handled treble and bass pickup, like a two‑way speaker in reverse. More recently, Shure have perfected their Dualdyne design, a single moving‑coil capsule with an active front and a passive rear diaphragm, which helps to improve the pattern consistency and minimise proximity effect. Austrian Audio have taken yet another different path with the OD505: the second, passive capsule is connected in reverse polarity, with the aim seemingly being to ensure that handling noise is picked up equally by both capsules and cancelled out, whereas wanted audio is captured only by the active, front‑facing element.

Beneath The Surface

Like the CC8, the OD505 is supplied in a robust but hugely oversized padded carry case, which also contains a simple plastic standmount of familiar design. The mic itself is on the large side, too, being nearly 200mm long and over 50mm wide at its thickest point; in overall size and shape it’s quite similar to the old AKG D202 ‘rocket ship’, but with a conventional mesh grille. The mic’s diecast metal shell looks like it would withstand most forms of abuse, and the black exterior is nicely offset by gaps that reveal a red‑painted interior. These gaps exist to facilitate Austrian Audio’s Open Acoustics Design, which makes the entire capsule assembly open to the air not just at the front and sides but to the rear also.

Austrian Audio’s 3D Pop Noise Diffuser is a conical filter designed to disperse plosives before they reach the diaphragm.The OD505 is described as having a supercardioid polar pattern, and the published charts suggest that this is maintained very accurately between about 250Hz and 2kHz. Either side of that, the rear ‘tail’ is less apparent and the pattern more straightforwardly cardioid. The frequency response chart also shows a substantial presence peak extending from about 1.5 to 10 kHz and reaching +6dB at 4‑5 kHz.

Unlike some stage mics, the OD505 is not designed to give a flat response in the low end when used close up. There seems to be a fixed roll‑off in the low bass, but at 5cm operating distance, proximity effect will give you a 10dB boost in the 100Hz area. Austrian Audio have equipped the mic with a switchable 12dB/octave high‑pass filter, engaged using a slide switch that is sensibly recessed so you can’t accidentally flick it on or off. However, this turns over at 120Hz, so unless your vocalist has a very deep voice, it actually makes little difference to the additional warmth introduced by the proximity effect. Its action is much more apparent on spill from drums and bass instruments.

Ready To Go

In general, there are two schools of thought when it comes to designing microphones for live sound applications. On the one hand, manufacturers such as DPA make their mics as neutral as possible, reasoning that if the live sound engineer wants something different, he or she can apply EQ as needed. By contrast, many other manufacturers take the view that if you start with a flat response, most of the time you’re going to end up applying the same sort of EQ curve anyway, so it might as well be baked into the microphone. With the OD505, Austrian Audio seem to incline towards the latter view, and that wide treble lift is both readily apparent and the sort of thing that you’d expect to find in a basic vocal sound preset on a digital console.

When used close up the OD505 has a pleasant but noticeably ’scooped’ tonality which is not entirely unreminiscent of Austrian Audio’s headphones.

For comparison purposes, I dug out my Shure Beta 57A, another supercardioid moving‑coil mic. Side by side, the OD505 has a lot more going on in the 100‑150Hz region, and even with that 120Hz filter engaged, it’s the richer‑sounding of the two. It also sounds quite a bit more present in the upper midrange — crisp and almost airy — whilst the 57A feels more solid and focused in the 1kHz area. Or to put it another way, when used close up the OD505 has a pleasant but noticeably ’scooped’ tonality which is not entirely unreminiscent of Austrian Audio’s headphones.

Off‑axis pickup is pretty clear and free from obvious coloration, though of course it will never be as good as a small‑diaphragm capacitor mic in this regard. Inasmuch as I was able to devise a fair test of handling noise, I couldn’t discern much difference between the OD505 and the Beta 57, though I wasn’t able to perform this comparison in a live context. The pop protection afforded by the 3D Diffuser is impressive, though, and even with the high‑pass filter switched out, I found it quite hard to generate obnoxious plosives.

All in all, the OD505 delivers what I think could justifiably be called a ‘mix ready’ sound. With most singers and most PA systems, you could plug it in and expect to get something that sounds right with minimal additional work beyond keeping half an ear out for that proximity boost. That sound won’t be perfect for all vocalists, but it’ll work well more often than not, leaving you more time to spend replacing broken DI boxes, figuring out why nothing is coming out of the acoustic guitar, locating the missing bass player for soundcheck and fending off impossible requests from band members. Oh, and mixing the show, of course.