What actually happens when you press play? Here's the technology behind the sound.
10 independent frequency bands, each with two overlapping buffer variants that crossfade using equal-power envelopes. You get continuous sound with no audible loop points, even after hours of listening.
10 frequency bands from 20 Hz sub-bass to 17 kHz ultra-high treble, each with independent gain control and smooth interpolation. The same type of EQ audio engineers use in recording studios.
Head-Related Transfer Function processing simulates how sound arrives at your ears from different directions in 3D space. 9 layouts position the frequency bands around you, and with AirPods Pro/Max, head tracking keeps the sound anchored as you move.
A 2048-point FFT analyzer uses your microphone to show ambient noise across 10 frequency bands in real time. You can see which frequencies are loudest in your room and adjust the EQ to match.
Each band has a slow, independent volume oscillation (one cycle every 2 to 5 minutes). It keeps the sound from feeling static over long sessions, the way real ambient noise shifts slightly over time.
Built with Swift and AVFoundation, running natively on Apple silicon. The audio engine uses Core Audio for low-latency processing, with a dynamics limiter to prevent clipping.
From 20 Hz sub-bass you can feel to 17 kHz ultra-high frequencies at the edge of hearing.
20 Hz
Sub-Bass
More felt than heard
60 Hz
Low Bass
Warmth and depth
125 Hz
Bass
Body and fullness
250 Hz
High Bass
Lower vocal range
500 Hz
Low Mids
Upper vocal range
1 kHz
Mids
Core speech frequencies
2 kHz
High Mids
Presence, clarity
4 kHz
Low Treble
Brightness, detail
8 kHz
Treble
Air, sibilance
17 kHz
Ultra-High
Highest audible range
Each layout positions the 10 frequency bands differently in 3D space around you using HRTF processing.
Bands evenly distributed around you
Traditional 5.1 positioning
Sound concentrated in front
Extra-wide left-right spread
Enveloping sound from all directions
Optimized for headphone listening
Bass behind, treble in front
Sound positioned behind you
All bands centered, no spatial processing
48 kHz stereo, the same sample rate used in professional film and music production.
HRTF (Head-Related Transfer Function) simulates how sound reaches your ears from different positions in 3D space. Quilence uses Apple's HRTF engine with 9 layouts to position frequency bands around you through any headphones.
No. All audio processing happens entirely on-device in real-time. Nothing is recorded, stored, or transmitted. Microphone access is optional and can be revoked at any time.
Each frequency band has a subtle, independent oscillation at extremely low frequencies (one cycle every 2–5 minutes). This prevents the brain from habituating to a perfectly static sound, making extended listening more comfortable.
Quilence uses high-quality audio sources processed through a multi-layer crossfade engine. Each of the 10 frequency bands has two overlapping buffer variants that blend together, so you never hear a loop point.
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