The complete broadcast chain.
Leveler, five-band AGC and compressor, EQ, stereo enhancer, clipper and true-peak limiter, with eleven factory formats to start from.
See the signal flowBroadcast audio processing
Every record at its best. Every voice easy to hear.
aircove is a broadcast processor built for the people on the other end of the dial. It makes a hundred records from a hundred mastering rooms sound like one station, keeps the presenter clear between them, and never gives a listener a reason to reach for the volume. It's been on the air around the clock as the processor behind Circa's music station.
“It was always about the music, the presenters, the listeners.”
Nicholas Young, founder
24/7on the air, unattended, running Circa's station
−0.02 to −0.20LU from calibration: where 17 library records landed with per-programme trim
11factory formats, from CHR to Classical
1.8 LUloudness range on air, measured beside an Optimod holding 3.1
The aircove family
One processor, and three ways to watch it.
Your processor's meters, wherever you are.
Live meters and the running settings, streamed to any browser or phone. Look all you like; nothing changes unless you've allowed it.
More informationThe console in your pocket.
An iPhone and iPad app for the engineer minding a processor in a building across town.
More informationTune from any browser.
The same controls and meters in a page, drawn from the processor's own settings, so a slider can't offer a value the processor would refuse.
More informationWhy a station needs a processor
A hundred mastering rooms, one station.
Put a hundred records on shuffle and each arrives at a different loudness, with a different balance and a different crest factor, with a presenter talking between them. Your listener hears that as riding the volume all afternoon. A processor earns its place in four ways.
Range your listener can live with
A record with 12 dB between its quiet verse and its chorus sounds wonderful in a studio and disappears under road noise in a car. The leveler and the five-band compressor bring that range down to what the room can carry, and the rung you pick decides how far: about 2, 4 or 8 LU.
One station, not a hundred masters
Programme changes source every three minutes. The multiband AGC brings each band to the same place on every record, the compressors add density without a kick drum ducking the vocal, and the house balance pulls every master toward one measured tone, which becomes your station's signature.
A presenter who's easy to hear
A voice has lopsided peaks that a limiter grabs before the words get loud enough. The phase rotator evens them out when the host says someone's talking, lowering peak-to-RMS by about 1 dB, and the leveler brings a quiet read up to sit with the music around it.
A ceiling nobody crosses
A lossy encoder turns an over into distortion you'll never see on a meter. The true-peak limiter reads a 4x oversampled copy of the signal, so it holds the ceiling between samples as well as on them, and the output lock keeps the programme on your calibration.
The trick, and it's the one broadcast processing has chased for fifty years, is doing all of that while your listener believes nothing's been touched. No spec sheet proves that, so the best test is still long-term listening: run it over your own library and live with it for an afternoon.
Signal flow
Every stage gets its own timescale.
Four stages control level, and four level controls moving at the same speed will fight and pump. So the limiter works in milliseconds, the leveler over seconds, and the band AGC over tens of seconds. Stages marked off cost nothing until you turn them on.
- Input guardCorrupt samples from upstream are caught and counted before any filter can lock up on them.
- Silence detectorReads the input and reports dead air. It never touches the audio.
- Subsonic high-pass15 Hz, 24 dB/oct. Turntable warp and DC come out before anything measures them.
- Phase rotator offAll-pass sections that even out a voice's lopsided peaks, engaged per element by the host.
- Stereo enhancer offLifts L−R above 150 Hz toward a target width. The mono sum is untouched.
- Leveler (AGC)Window-gated wideband AGC, with an optional bass band split off at 200 Hz.
- Five-band crossoverLinkwitz-Riley, allpass-aligned, at 150, 420, 1600 and 6200 Hz.
- Multiband AGC and house balanceSlow, bounded per-band leveling toward targets measured off your own library.
- Band expander offPulls a band down under its noise floor, so vinyl surface noise isn't lifted in the gaps.
- Band compressorsFive compressors with optional look-ahead and coupling between neighbours.
- Band restoration offGives each band back the tone its own compressor took.
- Static EQ and HF enhancer offLow shelf, three parametric bands, high shelf, and an adaptive shelf that lifts a dull record.
- Output gainOperator makeup, the output lock's trim, and the per-programme trim.
- Clipper off4x oversampled, with a separate bass clipper and distortion control.
- True-peak limiter2 ms look-ahead brickwall on a 4x oversampled detector.
- Output metersBS.1770 short-term and gated integrated loudness, per programme.
Features
Measured, not guessed.
Every setting in aircove has a measurement behind it, and every claim below comes from a test you can run again.
Loudness
- Every record at the same level. The leveler lifts a quiet passage and tames a loud one inside a deadband, with 18 dB of lift, 12 dB of cut, and a fade hold that lets an outro fade.
- Bass that doesn't drag the mix. The two-band AGC moves the bass on its own: a bass line swinging 10 dB moved the mids 0.36 dB, against 3.86 dB with one band.
- On calibration, all day. The output lock measures what actually leaves the processor and holds it to your target: −23 LUFS for EBU R128, −24 for ATSC A/85, or your own.
Dynamics
- Density without ducking. Five bands at the classic broadcast corners, so a kick drum pushes the sub down instead of the vocal.
- The same grip on every record. A slow multiband AGC brings each band to the same place before the compressors see it.
- No moving notches. Band coupling keeps neighbouring bands from drifting apart at the crossovers, and up to 10 ms of look-ahead meets each hit cleanly.
- Four measured rungs from dense to open, each holding about twice the range of the one above.
Peak control
- Loud without the grit. The clipper is oversampled 4x, so its harmonics are filtered out instead of folding back as harshness.
- A kick that doesn't smear the vocal. The bass clipper handles the low end on its own; intermodulation on a two-tone test fell about 15 dB at the same loudness.
- Clean mids when it's pushed. Distortion control cut clip distortion between 0.6 and 2 kHz by 15 to 32 dB on every test record.
- Nothing over the ceiling. The true-peak limiter holds within about 0.1 dB of its ceiling, between samples as well as on them.
Tone and stereo
- One sound for the station. House balance pulls every master toward one tone, measured off your own library.
- No tilt from compression. Band restoration gives each band back what its compressor took.
- Wider, and still mono-safe. The stereo enhancer widens the image above 150 Hz without changing the mono sum at all.
- Voices that cut through. The phase rotator evens out a voice's lopsided peaks, about 1 dB across 108 voices, so a presenter sits louder at the same peak.
Built for the 3 a.m. nobody's awake for
- Fails safe. A bad setting costs you that setting, never the air.
- Retune live. Changes take effect mid-record, without a click.
- Dead-air detection. Silence on the input is reported, so your automation can act on it.
- Updates never change your sound. New stages arrive switched off, and the output is identical to the last version, bit for bit, until you turn them on.
Watching it remotely
- Watch from anywhere. Live meters and the running settings stream to a browser or phone, and the audio never waits on a slow connection.
- Changes go through you. A remote edit is checked in full before anything's applied, and nothing changes unless you've allowed it.
- Aircove Tune for iPhone and iPad, and a web console for any browser, both drawn from the processor's own settings.
Factory formats
Eleven formats give you a quick start for the sound you're after.
A format sets the whole chain at once: the dynamics, where the bands split, how hard each band is compressed, and the standing tilt across them. Every tone trim sits within 3.5 dB, so a format leans a band rather than equalising it.
| Format | Holds | Sounds like |
|---|---|---|
| CHR, Urban, Hot AC, Rock | ~2 LU | Loud, dense, the same on every record |
| Talk | ~2 LU | An intelligibility setting, and it's supposed to sound wrong on music |
| Reference, AC, Country, Classic Rock | ~4 LU | Present without being relentless |
| Jazz, Classical | ~8 LU | Barely touched, for recordings that don't want help |
The dynamics under each format come from the measured rung ladder: Smooth holds about 2 LU, Drive about 4, Glide about 8, and Off keeps the record just as it arrived (the limiter still runs, since a ceiling isn't a format choice).
Compared with an Optimod 5950
Every audio block that matters.
These are the audio-processing rows of Orban's own comparison sheet (revised 16 April 2024), with aircove's answer beside each. It's about which blocks exist, not how they sound.
| Block | Optimod 5950 | aircove |
|---|---|---|
| 2-band gated AGC | Yes | Yes |
| Multiband compressor | 2 or 5 bands | 5 bands |
| Compressor look-ahead | Yes | Yes, 0 to 10 ms |
| Downward expander | Yes | Yes, per band |
| Parametric EQ | 3-band | 3-band |
| Program-adaptive HF enhancer | Yes | Yes, lift only |
| Stereo enhancer | Two styles | One style, mono-safe |
| Anti-aliased clippers | Yes | Yes, 4x oversampled |
| Bass clipper | Yes | Yes |
| Clipping distortion controller | Program-adaptive | Yes, fixed 150 Hz to 4 kHz |
| True-peak look-ahead limiter | Yes | Yes |
| BS.1770 / R128 control and meters | Yes | Yes |
| Silence detector | With alarm | Reports; the host alarms |
| Subharmonic synthesizer | Yes | No, deliberately |
| FM composite, MPX, BS.412, RDS | Yes | No: aircove feeds encoders, not an exciter |
aircove also has stages the sheet doesn't list: a multiband AGC and house balance ahead of the compressors, band restoration, an output lock, and an offline measurement of each record's delivered loudness.
On the air, side by side
Measured against Orban, live.
On 27 September 2026 we recorded Circa's station and SomaFM Indie Pop Rocks, which runs Orban processing, at the same time for fifteen minutes. Both are 128k AAC streams, and each was gained to −16 LUFS before anything about its sound was measured, so neither wins by being louder.
| Measure | aircove | Orban | Reading |
|---|---|---|---|
| Loudness range (EBU LRA) | 1.8 LU | 3.1 LU | Tighter |
| Time at the ceiling | 0.40% | 1.23% | A third as much |
| True peak after decoding | −10.3 dBTP | +0.4 dBTP | Never overs |
| Delivered against calibration | −24.1 / −24.0 | – | On target |
| Stereo width (side to mid) | −6.7 dB | −10.3 dB | Wider |
| Crest, 1 s median | 13.6 dB | 12.9 dB | More peak above the body |
| Kick punch | 5.69 dB | 6.28 dB | Behind |
| Snare punch | 5.19 dB | 6.24 dB | Behind |
| Movement inside a phrase | 0.90 dB | 1.21 dB | Flatter |
aircove holds the range tighter than an Optimod on air and never lets a peak through, while Orban still lets the drums hit harder and the music breathe more inside a phrase. Two stations can't play the same records, so treat the punch figures with care: Orban's own snare moved 1.2 dB between two captures a day apart. Drums that cut through are exactly what we're tuning for next, and this table is how we'll know when we get there.
Early access
For the hardcore.
If you're the engineer who reads the spec sheet twice and A/Bs a release time over a whole afternoon, join the list. You'll hear from us before anyone else: early builds, new stages to try on your own air, and what's coming next.
For developers
Put the processor inside your own playout.
The same chain is available as a Rust library: interleaved audio in place, any block size, and nothing allocated once it's running. If you've got an audio callback, you've got somewhere to put it.
As a library
use aircove::{Chain, Preset}; // Pick a format, and a calibration in LUFS. let mut chain = Chain::new( 48_000, 2, Preset::Chr.config_for(-23.0), ); // Interleaved f32, in place, any block size. let report = chain.process(&mut block); if report.non_finite_scrubbed > 0 { // Something upstream is broken. Log it loudly. }
On your own music
cargo run --release --example process_wav -- \
in.wav out.wav --preset smooth
It reads a WAV, runs it through a rung, writes it back in the same format, and reports loudness, range, peak and how far the AGC rode. Every number on this page came from particular records on particular runs, so the best way to know what the chain will do to yours is to point this at them and listen.