Features

Everything the program does, stated plainly. Limits included.

Live 3D waterfall

The waterfall is the real spectrum of the played signal: the engine computes it, the interface draws it.

Resolution: 160 bands, 0 Hz – 24 kHz. The bands below 75 Hz come from a separate analysis with about 3 Hz resolution.
Speed: Up to 60 frames per second. Six quality levels from the 2D view to 3D at 60 fps; the visualization can also be switched off.
Time steps: 60, 120 or 180 steps.
Viewpoint: 3D isometric, side profile or top view (spectrogram).
Flow direction: Down or up; keystone correction makes the back edge of the mesh narrower or wider.
Load: It does not draw without music or in a fully covered window; if the window is visible but another one is active, at most 30 fps.
Pre-ringing: In linear-phase modes (FIR, FFT, SPM) a label shows that pre-ringing is possible; the program does not exaggerate it.

Parametric EQ

Up to 32 bands and 12 filter types; editing happens on the curve.

Processing modes: IIR, FIR, FFT and SPM; FIR, FFT and SPM are linear-phase. Decramp (oversampling) in IIR and FIR mode.
Filters: RLC, BWC, LRX and APO filter modes; x1–x4 slope.
Editing: Drag points on the curve, adjust Q with the mouse wheel, double-click to add a band; the selected band's values can also be typed.
Preamp: If the curve would clip, the preamp follows the curve's peak; for an imported profile it uses the profile's preamp. With the EQ off (Bypass) it has no effect, so Bypass gives the original signal.
Profiles: The active profile's name is shown in the header; profiles are kept after a restart.
Smart focus: The interface scrolls freely: the charts accept wheel input only after you click them, so the wheel does not change bands or filter values by accident.

AutoEq profiles and import

Profiles for more than 8,850 headphones and earphones can be searched and imported in one click.

Source: The official repository of the AutoEq project (MIT license) on GitHub; the list and the chosen profile are downloaded from the interface.
Manual import: From a file or pasted text: AutoEq ParametricEQ, Equalizer APO and REW parametric filter lists, with PK / LS(C) / HS(C) / LP / HP / NO / AP / BP types and a Preamp line. Disabled and unsupported lines are skipped, and it reports how many and why.
Not applied: Graphic EQ (GraphicEQ) and CSV frequency responses.
Modification: An imported profile stays untouched; a manual change creates your own profile named “– modified”.

Phase and group delay

The engine computes the curves with the same filters that process the sound.

Curves: EQ curve, phase and group delay on one chart, each can be switched on and off.
Linear phase: In FIR, FFT and SPM modes the phase is linear; the delay is the processing delay.
Without the engine: If the engine is not running, the interface draws an approximate curve.

Convolver (impulse response)

Load an impulse response and use it on the played audio.

Format: WAV or IRS; loaded with a preview. The impulse response is converted to the playback sample rate.
Settings: IR width, autogain, dry / wet, input and output gain.
Latency: Processing latency does not grow with the length of the impulse response; with power-of-two block sizes there is no extra latency, otherwise at most one block.
Room correction: Load a correction filter designed from measurements (e.g. from REW), not the raw impulse response of the room.
Profiles: Several WAV files can be imported at once; each becomes a profile for which the program keeps the impulse response.

Limiter, crossfeed, bass enhancer and more

The other modules of the chain; each can be switched on and off separately.

Limiter: 12 modes, oversampling (True Peak too), dither, lookahead / attack / release, stereo link, ALR. Defaults: −1.0 dB threshold, True Peak, 24 bit. A safety net, not hearing protection.
Crossfeed: Three presets or a custom setting: cutoff frequency 300–2000 Hz, level 1–15 dB.
Bass enhancer: Psychoacoustic missing-fundamental synthesis; with amount, harmonics, scope, floor, blend and listen parameters.
Mono: Bass mono-ization; the cutoff is adjustable between 40 and 250 Hz (default: 100 Hz).
Autogain (experimental): Adjusts the short-term (3 s) loudness (EBU R128) to the chosen target: −18 LUFS by default, at most ±6 dB. Off by default.

Magic Touch

An automatic, restrained enhancer: it analyses the recording and adjusts only what is missing or distracting.

Character: Natural, Warm, Bright, Spacious.
Content: Automatic (with detection), Music, Speech, Archive recording.
Restoration: Removal of 50/60 Hz hum, click repair, noise reduction.
Control: Intensity slider, level-matched A/B comparison, detailed diagnostics.

Burn-in (headphone run-in)

A noise signal for running in headphones, with safety limits; started from the header.

Signal: Pink, brown and white noise in turns, with a 20 Hz high-pass filter. No square wave.
Levels: −30 dBFS average level and a soft −18 dBFS peak limit (it does not clip); a 10-second fade in and out.
Pauses: 1 minute of silence every 10 minutes.
Modules: While it runs, the EQ, the Convolver, Autogain and the other modules are switched off, and restored afterwards. If the interface closes during a run, the modules are restored to their pre-run state at the next start.
Keep awake: It prevents the computer from sleeping (on Windows; on Linux with systemd-inhibit), the display may sleep. On Linux the block ends when the interface exits, also after a crash.
Caution: Set the volume low. It comes with a disclaimer: the program takes no responsibility for any damage.

Built-in player and library

The music you play goes through the Aqulify chain, so correction and analysis apply to your own files too.

Formats: FLAC, WAV, MP3, Ogg Vorbis, ALAC (.m4a, .alac, .caf) and Opus.
Output: On Linux to the “Aqulify” output, on Windows to the default device (WASAPI, through the Equalizer APO chain), on macOS to Core Audio; all three go through the DSP chain.
Library: The music folders you choose and their subfolders, albums, cover art (embedded or the folder image). A cache and change tracking make loading after a restart fast.
Play queue: An album, folder or track list from a chosen track, next and previous. At the same sample rate tracks follow each other without a gap. The queue is restored after a restart but does not start by itself.
Lists: Your own playlists, and smart lists with your own rules; the play log counts a track after 30 seconds or half its length.
Other players: It also controls another player running on the computer through the system media controls: SMTC on Windows, MPRIS on Linux, MediaRemote on macOS.

System-wide operation

The engine processes the system's audio, so it works on the sound of any player; settings are kept after a restart.

Linux: A PipeWire virtual output named “Aqulify”; what the system sends there goes through the DSP chain to the real sound card or DAC. The engine is a systemd user service that starts at login. On Ubuntu / Debian, Fedora, Arch and openSUSE the installer detects the package manager; for Fedora and RHEL there is also a ready-made RPM package.
Windows 10 and 11: Equalizer APO plugin; the installer detects or downloads Equalizer APO and places the plugin at the end of the chain. The engine is a tray-icon background app, the interface runs in its own window.
macOS: Menu-bar app (Apple Silicon and Intel, macOS 12 or newer). From macOS 14.2 the system audio is handed over by Core Audio without a driver (it asks for permission); on older systems the free BlackHole 2ch is required.
Interface: In Hungarian and English, starting in the system language; in its own window on all three systems.
Data and network: It does not collect or send personal data. By default it listens only on your own computer, and uses the network only to download the AutoEq list and profiles, and the Support button opens the Revolut page.