Nearly all recorded music, film, and broadcast content is mixed for speaker playback. Speakers let both ears hear both channels — the brain builds a spatial image from the subtle timing and frequency differences that result. Headphones bypass that process entirely: each ear receives only one channel, collapsing the sound stage to a point between the ears. Vocals move inside the listener's head, reverb is exaggerated, and the spatial relationships between instruments are lost.

Eilex Headphone converts standard stereo to binaural audio in real time, restoring the spatial presentation of a reference speaker system. The result is a natural, externalized sound stage that preserves the recording's intended imaging — through any headphones or earphones.

How it works

Eilex Headphone reconstructs the acoustic conditions of speaker listening through three mechanisms:

Cross-feed. In a real room, both ears hear both speakers. Eilex Headphone feeds a controlled portion of the opposite channel to each ear, replicating that natural condition. An inter-aural time delay (ITD) is applied to the cross-fed signal, preserving the directional cues that the brain uses to localize sound sources.

HRTF (Head Related Transfer Function). When sound travels from a speaker to the ear, it reflects and diffracts around the listener's head, outer ears, torso, and shoulders. These interactions create complex frequency-response changes that the brain interprets as spatial information. Eilex Headphone models this using HRTFs derived from impulse responses (HRIRs) measured at both ears. The reference sound stage is set at 60 degrees — the standard studio monitor layout.

VIR filter precision. The combined HRTF for direct and cross-feed paths produces a frequency response too complex for conventional FIR or IIR filters to reproduce accurately. Eilex's proprietary VIR filter handles it with full precision in minimum phase — matching the behavior of natural acoustics. This is the same filter architecture that underpins PRISM speaker correction, applied here to binaural processing.

What it preserves

Eilex Headphone is designed to be transparent to the headphone's own sonic character:

• Works with all headphone types — over-ear, on-ear, earbuds, and in-ear monitors. No per-model tuning is required for the core binaural processing.
• Preserves the manufacturer's tonal signature — compensation coefficients are carefully composed to leave each headphone's intended sound character intact.
• Reduces listener fatigue — externalized imaging and natural cross-feed reduce the perceptual strain of prolonged headphone listening.
• Hi-Res Audio compatible — operates at all sampling rates and with all formats, lossless and lossy.

Where Eilex Headphone fits

Eilex Headphone is designed for any product where users listen through headphones — smartphones, laptops, tablets, dedicated headphone amplifiers, and TV headphone outputs.

It pairs naturally with complementary Eilex technologies:

• Harmony and Focus — recover detail and bandwidth lost to lossy compression, improving the source material before binaural processing
• HD Remaster — upconverts standard-resolution audio to hi-res quality