Monitoring Controller

If you mix on a single pair of speakers and never check your mixes on headphones or a second set of monitors, you can get by without one. But as soon as you want to switch between speakers and headphones, calibrate your listening level, protect your monitors from accidental peaks, or reference at low volume without losing bass -- a monitor controller becomes essential. A software monitor controller gives you all of this without extra hardware, without adding a DA/AD conversion to your signal path, and without taking up desk space.

A hardware monitor controller sits between your DAC and your speakers, which means an extra DA/AD conversion in your signal path -- adding potential noise and coloration. A software monitor controller works in the digital domain before your DAC, keeping your signal path clean with zero added conversion. Most hardware units -- even those costing $300 to $3,000 -- also lack loudness compensation, speaker protection limiters, and advanced routing like Mid/Side monitoring. Monitor Controller Compact Edition provides all of these features for a fraction of the cost. Pair it with any MIDI controller for physical knob control, and you get the best of both worlds.

Hardware monitor controllers like the Mackie Big Knob, PreSonus Monitor Station, or Grace Design M905 handle volume and speaker switching in the analog domain -- but they add an extra DA/AD conversion stage to your signal path. A software monitor controller works entirely in the digital domain, before your DAC, keeping your signal clean. It can also add intelligent features that hardware cannot: ISO 226 loudness compensation, calibration presets across multiple standards, brick-wall limiting, and full remote control from your phone. The trade-off is the lack of hands-on control -- but any MIDI controller can be mapped to the app in seconds via MIDI Learn, giving you a physical knob on your desk. And unlike a hardware unit, a software controller takes up zero desk space.

For most home and project studios, yes. Here is how Monitor Controller Compact Edition compares to popular hardware units:

The main things hardware provides that software cannot are built-in DACs and physical headphone amplifiers. If your audio interface already has a good DAC and headphone output, software gives you more monitoring features at a fraction of the price. With MC Compact Edition, you can assign Output B to your interface's headphone output -- giving you independent volume, calibration, and loudness settings for your headphones.

The Fletcher-Munson curves (updated as ISO 226:2003 equal-loudness contours) show that human hearing perceives frequencies differently at different volumes. At low levels, you hear less bass -- so if you mix quietly, you tend to overcompensate by boosting the low end. Then your mix sounds boomy at louder levels. This is why mixes done at low volume often don't translate well. Monitor Controller Compact Edition solves this by applying real-time ISO 226 correction curves that keep your tonal balance accurate at any monitoring level.

The traditional advice is to always mix at 85 dB SPL. But that is too loud for most home studios and causes ear fatigue. A better solution is loudness compensation: corrective EQ curves based on the ISO 226 standard that automatically boost the frequencies your ears are less sensitive to at lower volumes. Monitor Controller Compact Edition applies this compensation in real time, so you can mix at comfortable levels without losing low-end accuracy.

At low listening levels, human hearing is less sensitive to bass frequencies. ISO 226 loudness compensation applies corrective EQ curves so your low end stays accurate even at quiet volumes.

Loudness equalization is a general term for adjusting audio levels to sound consistent. Loudness compensation (or loudness contouring) specifically refers to correcting for how human hearing perceives frequencies differently at various volumes -- based on the ISO 226 equal-loudness contours. Monitor Controller Compact Edition uses the latter: it applies scientifically-based EQ curves so your monitoring stays tonally balanced whether you listen quietly or loud.

Because of how human hearing works. The ISO 226 equal-loudness contours show that at low SPL, your ears are far less sensitive to bass. So when you mix quietly, you unconsciously boost the low end to compensate -- and then your mix sounds boomy when played back louder. This is the Fletcher-Munson problem. The solution is loudness compensation: real-time EQ correction that restores the low frequencies your ears lose at low volume. Monitor Controller Compact Edition applies this automatically using the ISO 226 standard, so your tonal balance stays consistent no matter how quietly you monitor.

The traditional recommendation is 85 dB SPL (per ITU-R BS.1116), which is where human hearing is most linear across the frequency spectrum. But 85 dB is too loud for extended sessions in most home studios -- it causes ear fatigue and can damage your hearing over time. Many engineers work at 70-79 dB for comfort. The problem is that at those lower levels, you lose bass perception due to the Fletcher-Munson effect. Monitor Controller Compact Edition solves this with ISO 226 loudness compensation: you can mix at whatever level is comfortable, and the app automatically corrects for the perceptual loss so your frequency balance stays accurate.

Yes -- that is exactly what this application was designed for. The ISO 226 loudness compensation adjusts the low end in real time, counteracting the natural loss of bass perception at quiet volumes. You get two modes: Relative mode leaves your sound completely untouched at normal listening level -- compensation only kicks in when you turn the volume down, so your reference listening stays exactly as you know it. Absolute mode uses your calibrated SPL level for scientifically precise correction at all times. Either way, you can mix at comfortable, ear-safe levels without sacrificing tonal accuracy.

No. That is exactly what Relative mode is for. At your normal listening level (0 dB on the volume knob), your sound is completely untouched -- no EQ, no processing, nothing changes. Loudness compensation only kicks in when you turn the volume down. So your reference listening stays exactly as you know it, and you only get correction when you actually need it: at lower levels where your ears naturally lose low-end perception. You can enable it and forget about it -- it will never get in the way of your trusted reference.

In Relative mode, your sound stays completely unchanged at normal listening level -- the compensation only activates when you lower the volume. This is ideal if you already know your room and trust your reference level: you keep your familiar sound, and the app only compensates when you turn down. In Absolute mode, the app uses your calibrated SPL measurement to apply scientifically precise ISO 226 correction at all times, regardless of volume. Relative mode is the easiest way to start -- no calibration needed, zero impact on your current listening, and it protects your tonal balance as soon as you lower the volume.

Yes. Monitor Controller Compact Edition lets you switch between two stereo speaker outputs (A/B) with a 40-millisecond crossfade -- no clicks, no pops. Each output has independent volume, calibration, loudness compensation, high-pass filter, and limiter settings. You can assign each output to a different audio device and switch instantly using the app, a keyboard shortcut, MIDI controller, or the iOS remote.

Monitor Controller Compact Edition gives you routing modes accessible with one click: Stereo, Swap L/R, Left only, Right only, Mid, and Side. The Mid mode sums your channels so you can instantly check mono compatibility and hear phase cancellation issues. Side mode lets you isolate the sides of your stereo image. A real-time correlation meter shows your stereo phase coherence from -1 (fully out of phase) to +1 (perfectly correlated), so you can spot problems before they reach your listeners.

Two independent stereo outputs (A and B), each with its own volume, calibration, loudness compensation, HPF, limiter, and routing settings.

Monitor Controller Compact Edition has two independent stereo inputs (A and B). Set Input A to your DAW and Input B to a reference player (like Spotify, Apple Music, or a separate audio player). Then switch between them with one click, a keyboard shortcut, or a MIDI button. Each input has its own trim control, so you can level-match your mix against the reference for accurate comparison. On macOS Sonoma and later, you can capture audio directly from any application without needing a virtual audio driver.

Yes. Assign Output B to your audio interface's headphone output and Output A to your speakers. Each output has its own volume, calibration, loudness compensation, and limiter -- so you can switch between speakers and headphones instantly with fully independent settings. Just name your outputs (e.g. "Mains" and "Headphones") for quick identification.

Monitor Controller Compact Edition includes four built-in calibration standards -- ITU-R BS.1116, EBU R128, SMPTE RP 200, and AES -- plus a fully custom mode where you define your own pink noise level and reference SPL target. Use the built-in test signal generator and an SPL meter to set your reference level. Once calibrated, the app displays levels in calibrated SPL rather than just dBFS, so you always know exactly how loud you are monitoring.

Accidental bursts of loud audio -- a DAW glitch, a dropped plugin, a hot signal from a new session -- can damage speakers and hurt your ears. Monitor Controller Compact Edition includes a per-output brick-wall limiter with 1ms lookahead that catches peaks before they reach your monitors. It also provides a safety high-pass filter (10-100 Hz, Linkwitz-Riley at 12, 24, or 48 dB/oct) that protects woofers from dangerous sub-bass energy. Both features work independently per output.

The simplest answer: mix at lower volume. But mixing quietly introduces the Fletcher-Munson problem -- you lose bass perception, which leads to poor mix decisions. Monitor Controller Compact Edition solves both issues at once: the ISO 226 loudness compensation keeps your frequency balance accurate at low SPL, so you can protect your hearing without sacrificing mix quality. The brick-wall limiter also catches unexpected peaks before they reach your ears, and the dim function lets you drop the volume instantly when you need a break.

Yes. Any device that sends MIDI works with the built-in MIDI Learn: map any CC or Note message to any function, including volume, mute, dim, output selection, routing modes, and more. Popular options include small MIDI controllers like the Korg nanoKONTROL, Behringer X-Touch Mini, or even a simple USB knob for volume. Stream Deck users can send MIDI commands to the app for one-touch switching between speakers, headphones, inputs, or routing modes. You can also use keyboard shortcuts, the iOS remote app, or the web remote from any browser.

Yes. A dedicated iOS app provides native remote control with real-time sync and haptic feedback. A built-in web remote is also available from any browser on your local network.

Not necessarily. Each input and each output can be configured independently: you can use a CoreAudio Tap to capture audio directly from any application (macOS Sonoma 14.2+), a virtual audio device, or a physical hardware input -- and you can mix them freely. For example, your DAW input can be an app capture while your reference input uses a virtual device, and each output can go to a different physical audio interface. On older macOS versions and Windows, virtual audio devices remain a flexible option.

It is a standalone application for macOS (12+, Apple Silicon and Intel). Windows support is coming soon.