SOUND

Product Introduction

1. Definition: SOUND is a native macOS menu bar application that functions as a real-time, per-application audio processing engine. It falls into the technical categories of system audio utilities, digital signal processing (DSP) software, and user interface (UI) enhancement tools.
2. Core Value Proposition: SOUND exists to solve macOS's fundamental limitation of having a single, system-wide volume control and no built-in equalizer. It provides granular, per-app audio management—including an 8-band parametric equalizer, independent volume sliders, and individual output device routing—directly from the menu bar without requiring virtual audio drivers or kernel extensions.

Main Features

1. Per-App 8-Band Parametric Equalizer: Each application playing audio on a Mac receives its own dedicated 8-band equalizer with frequency centers at 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1 kHz, 2 kHz, 4 kHz, and 8 kHz, offering ±12 dB of gain adjustment per band. This is implemented using a cascade of peaking filters processed via Apple's Accelerate framework for high-performance, low-latency DSP directly on the local hardware.
2. Independent Per-App Volume and Output Routing: Beyond system-wide volume, SOUND provides a discrete volume slider for every active audio source. Furthermore, it allows users to route any application's audio to a different output device than the system default (e.g., routing a browser to desktop speakers while pinning a communication app to a headset), a feature known as audio submixing.
3. Local-Only Processing with Preset Syncing: All audio processing occurs locally on the user's Mac in real time; no audio data is recorded, stored, or transmitted to external servers. Despite this local-first architecture, user-created custom EQ presets synchronize across multiple Macs via Apple's iCloud, blending privacy with convenience.
4. System-Wide Master with Per-App Exceptions: Alongside individual app controls, a "System" master EQ and volume control applies a global audio profile to all sound sources not explicitly overridden. This allows SOUND to function as both a traditional system-wide equalizer and a sophisticated per-app audio mixer.

Problems Solved

1. Pain Point: macOS lacks native, granular control over application-specific audio levels and tonal quality. Users cannot independently lower the volume of a loud browser tab, video call, or advertisement without affecting music or other critical audio streams.
2. Target Audience: This includes audio professionals and hobbyists (e.g., music producers, podcasters, video editors using DaVinci Resolve or OBS) who need to reference mixes; multitaskers and knowledge workers who juggle communication apps (Zoom, Discord) with media; and everyday users seeking to enhance music listening, movie watching, or gaming audio on their Mac.
3. Use Cases: Critical scenarios include: isolating and reducing the volume of notification sounds or video call participants during focused work; applying a "Bass Boost" preset to Apple Music while keeping system alerts flat; routing game audio to a high-quality DAC/amp while sending Discord chat to a headset; and correcting poor audio quality in specific streaming or video playback applications.

Unique Advantages

1. Differentiation: Unlike traditional Mac equalizers (e.g., Boom 3D, eqMac) that install virtual audio loopback drivers, SOUND leverages Apple's modern per-process audio tap APIs (Core Audio). This results in a lighter, more stable integration that doesn't modify the system's audio stack, eliminates driver conflicts, and requires no restart.
2. Key Innovation: The primary technical innovation is the implementation of a real-time, multi-application DSP pipeline within the constraints of macOS sandboxing and privacy permissions. By forgoing a kernel-level driver and using sanctioned system APIs, SOUND delivers professional-grade per-app audio routing and EQ with app-store compliance, enhanced security, and seamless user experience.

Frequently Asked Questions (FAQ)

1. Does SOUND for Mac slow down my computer or cause audio lag? No. SOUND is optimized using Apple's Accelerate framework for efficient, real-time processing on the CPU. It is designed for minimal latency and resource usage, ensuring audio stays in sync and system performance is unaffected during normal use.
2. Can I use SOUND to apply different EQ settings to two instances of the same app (e.g., two Chrome tabs)? No. SOUND controls audio at the process level, not the tab or window level. If two tabs (like YouTube and Spotify) run within the same browser process, they will share the single EQ and volume profile assigned to that application (e.g., Google Chrome).
3. Is SOUND compatible with professional audio interfaces and DAWs like Logic Pro or Ableton Live? Yes, SOUND works with any audio output device recognized by macOS, including professional USB/Firewire/Thunderbolt interfaces. However, for critical recording and mixing within a Digital Audio Workstation (DAW), audio engineers typically bypass system-level processing like this to ensure a pure, unaltered signal path.
4. How does SOUND's privacy model work if it needs "Screen Recording" or "Audio Capture" permission? The permission is a standard macOS security gate for any app that needs to access audio output from other applications. Granting it allows SOUND to process the audio stream in memory only. It does not grant the ability to record, save, or transmit that audio, which SOUND explicitly does not do.
5. What happens to my audio settings if I quit the SOUND application? All SOUND processing stops immediately, and your Mac's audio reverts to its default, unprocessed state. Your custom EQ presets and settings are saved locally and will be restored when you relaunch the application.