Parametric EQ on Mac

What Is a Parametric EQ and How Does It Work?

Parametric EQ differs from graphic EQ in flexibility. A graphic equalizer provides fixed frequency bands (31 Hz, 62 Hz, 125 Hz, and so on) with only a gain slider for each. A parametric equalizer lets the user choose the exact center frequency, adjust the bandwidth (Q factor), and select the filter type (peak, shelf, high-pass, low-pass, notch) for each band. Professional audio engineers use parametric EQ because it can target a narrow resonance at 3.2 kHz without touching nearby frequencies.

LitLink Pro includes a free virtual audio driver for Mac with per-app parametric EQ built into its routing engine. Each application gets its own independent EQ curve with adjustable bands, a visual frequency response display, and a master EQ that applies to all routed audio. The EQ processes audio in real time at the driver level, so latency is under one millisecond.

Common parametric EQ filter types include peak (boost or cut a specific frequency), high shelf (boost or cut everything above a frequency), low shelf (boost or cut everything below a frequency), high-pass (remove low frequencies below a cutoff), and low-pass (remove high frequencies above a cutoff). A typical five-band parametric EQ covers the full audible spectrum from 20 Hz to 20 kHz with enough bands to shape any audio source.

How Does macOS Handle Audio Equalization?

Core Audio is the low-level audio framework that manages all sound on Mac. The framework routes PCM audio buffers from each application to the selected output device (speakers, headphones, USB audio interface) without inserting any processing in the signal path. Apple removed the iTunes equalizer from the system level years ago, and macOS Sonoma and Sequoia include no replacement.

Apple Music has a 10-band graphic equalizer in its settings, but it only affects Apple Music playback. Spotify has no Mac equalizer at all (the mobile app does). Chrome, Safari, Discord, Zoom, and every other application output flat, unprocessed audio. Users who want equalization across multiple apps need a third-party solution that intercepts audio at the system or driver level.

Third-party system-wide equalizers like eqMac and Boom 3D apply a single EQ curve to all audio output. eqMac is free and open-source, with a 10-band graphic and parametric mode. Boom 3D costs $19.99 and adds 3D surround virtualization on top of its EQ. Both tools apply the same EQ to every application simultaneously, which is a limitation when different apps need different tonal profiles.

How Does Per-App Parametric EQ Differ from System-Wide EQ?

The distinction matters in every multi-app audio scenario. A system-wide EQ that boosts 3 kHz for voice clarity in Zoom also boosts 3 kHz in Spotify, making music sound harsh. A per-app EQ applies the voice boost only to Zoom while leaving Spotify at its natural tonal balance. Each application gets its own EQ profile that loads automatically when the app launches.

LitLink Pro achieves per-app EQ by intercepting each application's audio stream individually through the macOS Process Tap API. The EQ processing happens before the streams are mixed to the output device, so each app's frequency curve is independent. Users who also need per-app volume control on Mac get both features in the same interface, since volume and EQ are applied per-stream in the same processing chain.

System-wide EQ tools like eqMac intercept audio at a single point after all app streams have been mixed together. Once mixed, individual app audio cannot be separated for independent processing. The only way to EQ apps independently is to intercept their audio before the mix, which requires a driver that taps each process individually.

How Do You Apply Parametric EQ to Individual Apps on Mac?

• Install LitLink and enable System Audio Passthrough all app audio routes through LitLink's processing engine
• Open LitLink Pro and locate the target application every app producing audio appears in the list
• Click the EQ icon next to the app name opens the parametric EQ panel with a visual frequency curve
• Drag EQ points to adjust frequency, gain, and bandwidth the curve updates in real time as you drag
• Toggle the EQ bypass button to compare processed vs original instant A/B comparison without losing your settings

The visual EQ curve displays the combined frequency response of all active bands. Each band appears as a draggable point on the curve. Dragging horizontally changes the center frequency. Dragging vertically changes the gain (boost or cut in decibels). The Q factor (bandwidth) is adjustable through a secondary control. The curve redraws instantly as you drag, providing immediate visual feedback of the equalization shape.

LitLink Pro also includes a master EQ that applies to all audio after per-app EQ processing. The master EQ is useful for compensating headphone frequency response or room correction that should apply uniformly to all audio sources. Per-app EQ and master EQ stack: the app-specific curve processes first, then the master curve processes the result.

What Are Common Use Cases for Per-App EQ on Mac?

Podcast listeners often struggle with inconsistent audio quality across shows. One podcast may have boomy bass, another may sound thin. Per-app EQ in the browser lets you compensate for each show without adjusting global audio that affects music playback in a separate app. The EQ settings for each app save independently and restore automatically.

How Does LitLink Pro Compare to Other Mac EQ Solutions?

eqMac is the right choice for users who want a simple, free system-wide equalizer and do not need per-app control. The app provides a clean interface with both graphic and parametric modes. The limitation is that every application receives the same EQ curve, which creates compromises when apps have different tonal needs.

SoundSource by Rogue Amoeba is the closest competitor to LitLink Pro for per-app audio control on Mac. SoundSource supports loading third-party Audio Unit plugins per app, which is useful for professionals who already own AU equalizers and compressors. LitLink Pro includes its own parametric EQ built in and costs $20 less, making it the simpler and more affordable option for users who do not need third-party plugin support.