Spitfire Audio AIR Studios Reverb

Spitfire’s first effects plug‑in captures the unique ambience of an iconic London studio: AIR Lyndhurst Hall.

Thirty‑three years after its acquisition by Beatles producer Sir George Martin, AIR Studios Lyndhurst remains a sought‑after recording facility. While other London studios buckled under the weight of business rates hikes /the Home Recording Revolution /Brexit /Covid /Liz Truss (delete where inapplicable), AIR weathered the storm and emerged with a stellar client list (including Adele, Coldplay, Dua Lipa, Paul McCartney and Billie Eilish) and a string of award‑winning scores for blockbusters such as Gladiator, Interstellar, The Dark Knight, Inception, the Dune movies, Atonement, No Time To Die, Harry Potter And The Goblet Of Fire, Grand Budapest Hotel and All Quiet On The Western Front.

The studio’s popularity with film composers stems from the amazing acoustic of Lyndhurst Hall. Built in 1884 for congregational singing, this hexagonal, 5000‑square‑foot galleried space is blessed with a rich natural reverb that creates a glorious sonic halo around anything, from a guitar amp to a full symphony orchestra. AIR’s former Chief Engineer Geoff Foster describes the hall as “a creative space in which you just want to perform”, thus fulfilling George Martin’s vision of a musician‑friendly environment within a spectacular recording location.

AIR Lyndhurst Studios, Hampstead, London. Built in 1884, the former Lyndhurst Road Congregational Church was acquired by producer George Martin in 1991 and converted into a state‑of‑the‑art studio facility.

Over the years, two of Lyndhurst Hall’s most frequent visitors have been Hans Zimmer (composer of seven of the aforementioned soundtracks) and UK company Spitfire Audio, who recorded their first orchestral sample library at AIR in 2008 and subsequently returned to capture dozens more. This longstanding relationship has led to a significant double first: AIR Studios have given Spitfire unprecedented access to sample the acoustics of their historic studio space, allowing the samplemeisters to create their debut effects plug‑in, AIR Studios Reverb.

You can mix between eight different stereo mic signals and adjust the source radiation between five orientations.

Overview

AIR Studios Reverb, or ASR as we’ll call it, is a detailed convolution reverb plug‑in that uses Spitfire’s proprietary Virtual Positioning Technology to tailor the acoustics of the Lyndhurst Hall in any way you choose. This feature allows you to position your sound source anywhere in the hall while capturing the precise ambience of its acoustic spaces. You can mix between eight different stereo mic signals (see box) and adjust the source radiation between five orientations: you can also instantly switch the room from Spitfire’s standard orchestral layout (players facing the control room) to Hans Zimmer’s preferred orientation, which flips the whole setup by 180 degrees.

To generate the 67,000 impulse responses (IRs) required to model a large three‑dimensional space, Spitfire recorded full‑spectrum sine sweeps played through 10 ATC SCM25A Pro active monitors: the speakers were set up in a row and systematically moved across the floor to collectively cover 28 positions, thus providing full coverage of the performing area.

Swivel‑top stands were used to rotate the speakers between left, right, front and back orientations, with custom‑made wooden trays laid on the stand tops enabling each speaker to face upwards. In a repetitive rigmarole lasting a full week, overlapping sine sweeps were recorded for nearly four minutes for each orientation, then repeated as a safety backup. Not my idea of a fun listening experience, but a member of the recording team described it as “more calming than sampling”!

Main Controls

ASR’s Main Controls panel features Mixer, Source, Shape and EQ sections. The mixer houses eight stereo mic signals with individual fader, mute and solo controls along with an Interactive Hall Guide, a colour‑coded representation of the microphones showing their position in the hall. Included on the visualiser are a pair of linked diamond‑shaped icons (‘pucks’ in Spitfire‑speak) which show which way the input sound source is facing.

The Source page allows you to change how the input signal radiates in the space. It contains five faders corresponding to the left, right, front, back and up orientations, with an additional sixth ‘sub’ fader dedicated to IRs recorded in the 20Hz to 200Hz range. A circular control rotates the sound source through 360 degrees, with an interactive graphic showing the coverage area.

The Source page allows you to change how the input signal radiates in the hall. The ‘sub’ fader is dedicated to IRs recorded in the 20Hz to 200Hz range: set it to 100% and you’ll hear the hall’s natural low‑frequency response.

Shape is a term used to denote digital manipulation of the reverb’s envelope and length. Its three main controls are Direct Level (not to be confused with the wet/dry mix), which adds more transient response to the reverb entry and increases instruments’ initial attack; Early Level, which increases the volume of the initial reflections which occur between 50 and 80 milliseconds; and Late Level, which controls later reflections that constitute the main, smooth‑sounding part of the reverb.

The remaining Shape controls, Early Stretch and Tail Stretch, increase or decrease the length of the reflections. There are five stretch modes: Retro alters the IR’s playback speed but also affects its frequency, while Granular creates a grainy digital effect by looping selected cycles of the IR. The remaining Elastique modes stretch the reverb tail without changing the pitch: its pristine High setting is slightly slower to take effect and more CPU intensive, Low is less detailed but acts faster, while Mid falls somewhere in between.

Meanwhile, the more familiar EQ page offers five bands of parametric EQ with frequency, gain and Q settings determined by a set of nodes you can drag around on screen. You can place the EQ before or after the reverb, useful if you just want to (say) brighten the reverb without affecting the tone of the input signal.

You can adjust ASR’s five‑band EQ by clicking and dragging the on‑screen nodes.

Room Controls

A set of room controls at the top of the interface modify the hall’s physical characteristics. Hall Layout switches the room configuration between Spitfire’s preferred orchestral setup (Layout A) and Hans Zimmer’s back‑to‑front seating plan (Layout B), which affects both microphone and player positions: this has a significant effect on the overall sound, and achieves with a single mouse click what would take many hours to set up in real life.

In order to reduce the excessively long reverb of the old Lyndhurst church hall, the studio installed a large, motorised hexagonal canopy suspended from the vaulted roof: this reduces the reverb time to just under three seconds, a manageable acoustic for instruments and voices.

In ASR you can adjust the height of the canopy between low (4.5 metres), medium (seven metres) and high (9.5 metres), the higher positions creating longer reverb decays. You can also switch between two different absorption materials used on the canopy: Melatech gives a slightly softer, less reverberant timbre, while Wood creates a harder and more reflective sound. The reverb time can be further reduced by enabling Gallery Damping, which adds sound absorption to the three galleries overlooking the hall.

AIR Studios Reverb’s Mixer page contains eight stereo microphone signals and an Interactive Hall Guide, which shows the currently active mics and their positions in the hall.

Quick Controls

A simplified set of controls at the bottom of the interface provides quick access to important parameters: Input Gain governs the volume of the signal you send into the reverb, Mix controls the ratio of dry to wet signal and Output determines the overall volume of the plug‑in. The vital pre‑delay setting (which may be synced to your DAW’s bpm) creates a sense of space by delaying the onset of the reverb, while Stereo Width and Mono control the input signal’s stereo spread.

The ASR manual advises that making the source signal mono works well for solo instruments, while stereo is best for ensembles. Regarding the Mix setting, I’d also suggest that in most situations, using ASR as an insert requires a fair amount of dry signal in the mix, but when using it as a send it should be set to 100% wet.

ASR In Use

Rather than diving into the controls, I found it more fruitful to load some of ASR’s factory presets to see what the plug‑in is capable of. You can navigate the preset browser by clicking on pictures of instrument families, or by wading through an annoyingly non‑alphabetical master list. Having chosen Celeste, and loaded Soniccouture’s fine instrument of the same name, I was bowled over by hearing its close‑miked acoustic transformed into a pristine, ethereal and enveloping large hall ambience. Magical.

I tried the same preset with Soniccouture’s Grand Marimba (also great), Glockenspiel (exquisite) and Tubular Bells, which felt like being in Westminster Abbey on Coronation Day. The drily‑recorded VSL Appassionata Strings were given a new lease of life by ASR’s Expansive Strings preset, and using the Flute Solo preset with the similarly dry Flute 1 Vienna Instrument also gave great results. Ethereal Choir (which stretches the reverb to four seconds) sent the choristers straight up to heaven, while the all‑purpose The Hall worked wonders on a range of solo instruments.

Though a longer reverb suits orchestral percussion, the Percussion Tight Mini Hall preset’s 1.24‑second IR works much better for ethnic and cinematic drums — I applied it to Tom Holkenborg’s Mad Max Percussion and plaster fell off my music room ceiling. Used more subtly, the shortened reverb also adds a nice ambience to brass instruments and solo strings.

My verdict: as well as giving you the coveted AIR Lyndhurst epic orchestral sound straight out of the box, this lovely no‑gimmicks reverb is a great tool for adding hall ambience to dry and close‑miked instruments. Spitfire Audio and AIR Studios recording teams, take a bow.

I’m glad Spitfire have managed to capture the spirit of AIR Lyndhurst Hall in this excellent plug‑in...

Conclusion

You’ll notice I haven’t used the word ‘immersive’ yet: that’s because the review copy was stereo only. Happily, Paul Thomson has now confirmed that Spitfire are working on a multi‑out system that will be compatible with “as many variants of surround and immersive systems as possible”. This will be available as a free update in a matter of months, so if you’re itching to replicate Lyndhurst Hall’s 3D ambience in an immersive audio environment, you hopefully won’t have long to wait.

Though AIR Studios’ longstanding success is a cause for celebration, nothing lasts forever: other great London studios such as BBC Maida Vale, Angel Studios and Abbey Road have all come within a whisker of being sold for residential development at various times. Whatever the future holds, I’m glad Spitfire have managed to capture the spirit of AIR Lyndhurst Hall in this excellent plug‑in, which I strongly recommend to anyone looking for a wonderfully pure, big and beautiful reverb effect.