Studio monitor controller for macOS

If you mix on one pair of speakers, never check on headphones or a second pair, and always listen at the same level, you can get by without one. As soon as you want to switch speakers and headphones, calibrate your listening level, protect your monitors from a stray full-scale burst, or reference at low volume without losing the bass, a monitor controller becomes the missing piece. PHON gives you all of that in software, before your converter, with no extra box on the desk.

Not for the controller functions. PHON handles volume, source selection, speaker and headphone switching, mono and side checks, dim and mute, calibration and protection, in the digital domain before your converter. A hardware unit sits after the converter and, unless it is purely passive, adds a conversion or an analogue gain stage to the path. What hardware still gives you is a physical knob and a built-in headphone amplifier. For the knob, any MIDI controller maps to PHON in seconds. For the headphones, your audio interface already has an output.

For many stereo studios, yes. The core of any monitor controller is source switching, output switching and a calibrated volume, and PHON does all three without an extra conversion stage. It then adds what hardware cannot: ISO 226 loudness compensation tied to your calibrated level, a reference taken live from any application, calibration to broadcast, cinema and K-System references, a brick-wall limiter and safety low cut per output, LUFS and true peak metering, and remote control from a phone. If you need a built-in DAC, talkback or surround, you still need hardware.

For a stereo studio on the Mac, yes. PHON switches sources, speakers and headphones, holds a calibrated volume, and adds level-matched A/B against any app, ISO 226 loudness compensation and a limiter on each output, for €69 one-time. SPHERE goes further for surround and immersive work, cue and talkback, and bass management. The full comparison is on the PHON vs SPHERE Stereo page.

No. PHON plays one of its three outputs at a time, so it cannot keep a performer's headphones fed while your monitors are muted, and it has no talkback input. For tracking, use your interface's own mixer for the cue feed, or a controller built for it.

PHON runs at your interface's buffer size and shows the current sample rate and latency at the bottom of the window. It is a monitoring path, not a plugin in your session, so it adds nothing to your DAW's recording or playback latency. Per-application capture uses macOS Core Audio taps, which add a small buffer of their own on the captured source.

Both sources have to sit at the same loudness or the louder one always sounds better. MATCH measures the two for three seconds, to ITU-R BS.1770, and moves the input trim of the source you are not listening to, so what you are hearing never jumps and the two are already aligned when you switch. Both sources need to be playing; if the other one is silent the button says so and nothing changes. A double-click on the input trim undoes it.

Set source A to your DAW and source B to the application playing the reference: Spotify, Apple Music, a browser, a video player, another DAW. PHON captures that application directly on macOS 14.2 and later. Press MATCH: PHON measures both for three seconds and trims the one you are not listening to, so the two sit at the same loudness. Then switch with a click, a key or a MIDI button. Nothing is imported, nothing is added to your session, and your master bus is untouched.

A reference plugin lives on a track or the master bus and needs the reference as an audio file. PHON lives on the monitoring path and takes the reference from whatever is playing on the Mac. You do not rip, import or align anything, you do not bypass plugins to hear the reference clean, and you can compare against a streaming catalogue rather than the few files you happened to download. PHON also applies the same loudness compensation to both, with a separate amount for the reference, which was mastered at an unknown level.

The Fletcher-Munson curves, now standardised as the ISO 226 equal-loudness contours, describe how sensitivity to bass and treble changes with level. At low listening levels your ears hear far less bass for the same signal. Mix quietly and you push the low end up to hear it; play the mix loud and it is boomy. That is why quiet mixes often do not translate. PHON applies the ISO 226 correction for the difference between your calibrated reference and your current volume, so the balance you hear stays close to the one you would hear at the reference.

Loudness compensation is an equalisation that restores the frequencies your ears lose at lower listening levels, so the tonal balance you perceive stays constant as you turn the volume down. Done properly it is computed from the ISO 226 equal-loudness contours and from two known levels: the reference you calibrated and your current volume setting. PHON does exactly that, on the monitoring path, with the amount scaled by a percentage you set separately for your mix and for the reference source.

Loudness equalisation, or normalisation, matches the level of different programmes so they play back equally loud: a streaming service does it to your catalogue. Loudness compensation corrects how your hearing perceives the frequency balance at a given level, following the ISO 226 equal-loudness contours. They solve different problems. PHON does the second, and adds level-matched A/B so you can compare your mix and a reference at the same loudness.

Mix quieter. The reason people do not is the Fletcher-Munson effect: at 65 dB SPL you hear noticeably less bass, and the mix decisions go wrong. With PHON you calibrate once, then work at whatever level is comfortable; the compensation restores what your ears lose for the difference, and the brick-wall limiter and dim button keep the occasional surprise away from your ears. Sessions get longer, mixes still translate.

Because hearing is not linear. The ISO 226 equal-loudness contours, the modern form of the Fletcher-Munson curves, show that sensitivity to bass drops sharply as the level goes down. Mix quietly and you boost the low end to hear it; play it loud and it is boomy. Loudness compensation restores most of the bass your ears lose at low level, so your tonal decisions hold better when you work quietly. PHON applies it in real time from the ISO 226 contours, tied to your calibrated level.

The film and broadcast references sit around 78 to 85 dB SPL, where hearing is most linear. That is loud for a long session in a small room and hard on the ears. Most engineers actually work lower, between 65 and 75 dB SPL. With PHON you calibrate to the reference you choose, then work at whatever level is comfortable: the compensation corrects the perceptual loss for the difference, so the balance you hear at 68 dB SPL stays close to what you would hear at 83.

No. That button applies one fixed shelf regardless of level. PHON computes the correction from two numbers it actually knows: your calibrated reference SPL and the current fader position. At the reference it applies nothing; below it, the difference between the ISO 226 contours for that drop. Above the reference it stays out of the way by default, and you can ask it to compensate there too if you want.

No. At 0 dB, your calibrated reference, PHON applies no correction at all: no EQ, no processing, exactly the sound you are used to. The compensation only comes in when you turn the volume down, and it disappears as soon as you come back up. You can leave it on permanently and forget it. An amount control in percent lets you scale it, separately for your mix and for the reference source.

Yes. PHON drives up to three stereo outputs, each on any device and channel pair, so you can put your mains on the interface, an alternate pair on another device and headphones on the built-in output. Each output keeps its own input trims, pan, loudness compensation amounts, low cut and limiter, and switching is a click-free crossfade.

Open Settings › Calibration and choose a reference: EBU Tech 3276, SMPTE RP 200, K-20, K-14 or your own values. PHON plays pink noise at the reference level through one loudspeaker at a time, with the fader held at 0 dB; set your monitors or your interface’s output until an SPL meter at the listening position reads the target, then do the other speaker. From then on the meter reads in dB SPL.

Each output has a brick-wall limiter with adjustable threshold and release and 1 ms lookahead, so a DAW glitch or a hot new session cannot send a full-scale burst to your tweeters. A safety low cut, Linkwitz-Riley at 12, 24 or 48 dB per octave, keeps sub-bass energy away from small woofers. Limiter activity is shown on the meter. It acts on what passes through PHON: a DAW glitch, a hot session, a misbehaving plugin. It cannot act on anything that bypasses it or sits after it, such as an interface fault or a hardware gain change.

Swap (flip L/R), left only, right only, mid and side are one button each on the routing row, and mono sits on the numeric keypad or on any MIDI control you map to it. A correlation meter from −1 to +1 shows phase coherence continuously. The three low cut buttons, 80, 120 and 200 Hz out of the box, let you hear what a small speaker or a phone will keep of your low end. Each preset's frequency and slope can be changed in Audio Settings.

Yes. PHON ships with themes drawn from the palettes of Ableton Live, Logic Pro, Pro Tools, Cubase, FL Studio and Reaper, plus a dark and a light theme, switched from the menu bar. The window can also stay on top of the session.

Yes. MIDI Learn maps any CC or note to any function: volume, mute, dim, source, output, routing mode and more. A small controller such as a Korg nanoKONTROL or Behringer X-Touch Mini gives you a physical volume knob; for a Stream Deck, the PHON plugin puts outputs, routing, mute, dim, loudness, source and level on its keys, lit with PHON's state, and the volume on a Stream Deck + dial. The numeric keypad covers every monitoring action on its own, and the web remote works from any phone or tablet browser on your network.

No. On macOS 14.2 and later PHON captures applications directly through Core Audio taps, without a driver, a kernel extension or an aggregate device. Each source and each output is configured independently, so you can still use a virtual device or a hardware input where that suits you, for example a DAW routed through a virtual device on source A and Spotify captured per application on source B.

macOS 13 or later on Apple Silicon or Intel. Per-application capture needs macOS 14.2 or later; on macOS 13 you can use a virtual device or a hardware input as a source. PHON is a standalone application, not a plugin. A Windows version is in progress; per-application capture is a macOS facility and will not be part of it, so the Windows build will take its sources from hardware inputs and virtual devices. Subscribe below to be notified when it ships.

One purchase, one licence key by email, activation on up to two machines. The 14-day trial is the full application, with no credit card. Updates within version 1.x are free and arrive through the app.