Lossy compression strips harmonics from audio, but the perceptual impact isn't uniform across the frequency range. The upper frequencies — where clarity, intelligibility, and transient detail live — suffer most noticeably. Focus targets that region specifically, regenerating harmonics where they matter most for perceived audio quality.

The result is audio that sounds clearer, more detailed, and more present — without altering the tonal character of the original signal.

How it works

Focus generates 2nd-order harmonics from the existing signal, applied selectively to frequencies above approximately 2.5 kHz. Higher-order harmonics are effectively suppressed, keeping the output clean. Below 2.5 kHz, harmonic generation is deliberately reduced to avoid coloring vocals and lower-midrange content.

This band-specific approach is what distinguishes Focus from broadband harmonic processing. Rather than treating the entire spectrum uniformly, Focus concentrates its effect where compression damage is most audible — the presence and brilliance range that carries detail, articulation, and spatial cues.

The processing runs in a side-chain architecture: Focus does not alter the input signal directly. Harmonics are generated, filtered, and leveled in a parallel path, then blended back. This gives precise control over the effect and keeps distortion minimal.

Consistent across input levels

Typical audio exciters generate harmonics proportional to the input signal level. That works when the source material has a consistent reference level — but consumer electronics don't have that luxury. A TV cycles through broadcast, streaming, disc playback, and apps, with reference levels varying by 40 dB or more.

Focus maintains consistent performance regardless of input level. Whether the source is a hot broadcast signal or a quiet streaming feed, the harmonic enhancement behaves identically. This makes it reliable in mixed-source products where the audio chain must handle anything.

Where Focus fits

Focus is most effective as a preprocessor upstream of HD Remaster. By restoring upper-frequency harmonics before hi-res upsampling, Focus provides richer source material for HD Remaster to work with — producing a more natural high-resolution result than upsampling the compressed signal directly.

Focus operates in the time domain with minimal computational overhead, making it suitable for embedded deployment across a wide range of platforms.