Margaret Vardell Sandresky, L’homme armé Organ Mass (2025)

Audio Engineer

One of the most unique aspects of ambisonics recording techniques is versatility. In immersive/spatial productions, ambisonics’s role is relatively obvious and very effective. In traditional stereo productions, however, ambisonics microphones can positively trounce standard microphones in terms of adaptability. But why is this, and how does this highlight the fundamental difference in the expected listener experience between these two production paradigms?

The nature of immersive productions force the creator to relinquish a certain amount of control. They don’t know how, exactly, a listener will choose to experience the content. Will they sit in one place, staring straight ahead? Or, will they stand up, walk around, tilt their head, face different directions, or all four at once? Stereo productions do not force this particular concession. At any moment, the creator can definitively choose what the listener will hear, and (largely) how they will hear it; there’s not the same risk the experience be drastically altered mid-way through the content.

At its core, ambisonics depicts gradients of sound pressure from (at least) four physical directions related to a single point in space, often captured with four very close microphone capsules facing outwards from opposing vertices of a cube. Since the varying magnitudinal pressure (i.e. gradient) from each capsule is inherently associated with the direction its facing, a steerable sphere of sound is created when these capsules are joined together.

In immersive formats, this sound is usually steered as the listener moves their head. This makes for great sound fields and ambience. However, in stereo, ambisonics grants virtually unprecedented control over the production’s aesthetic during post. Didn’t capture the snare just right? No problem, you now have more options. Too much trumpet in the brass section? Just steer it slightly closer to the trombones. Want to record group backing vocals all at once but maintain a direct signal from each voice? Record once, duplicate the tracks, and steer each one to face each vocalist. Truly, the utility on display is virtually unparalleled. So, why aren’t we all using them all the time?

For one, there’s the price to performance ratio. First order ambisonics (FOA) microphones are often $1k and up, and that cost is split between 4 capsules. As a result, those capsules are often (though not always) inferior to those on a standard, single-capsule microphone at the same price. There’s also the fidelity: FOA is subject to spatial image smearing, loss of critical high frequency energy, and poor localization performance, all of which may be mitigated by higher order ambisonics capture. However, higher order ambisonics capture requires a higher order ambisonics microphone with more capsules at a continually increasing cost, which leads back to the initial problem. Further, regardless of the ambisonics order used, decoding this content into something usable is not a universal process, and poor decoding frequently leads to unintended auditory artifacts.

There are no silver bullets here, simply more tools for the belt. There is no replacement for attention to detail and careful forethought. An ambisonic microphone alone will never capture the paradoxically simultaneous detail and breadth of a well placed Decca tree over an orchestra, nor the quiet intimacy of two TLM 103s on a soft singer and her acoustic guitar’s twelfth fret. Of course, that doesn’t mean ambisonics doesn’t deserve a spot in the repertoire - it just means it’s important to understand that repertoire.

Provided here is a stereo recording of Gloria from Margaret Vardell Sandresky’s L’homme armé Organ Mass, recorded with a first-order ambisonics microphone and an NOS stereo pair, performed by David Preston.