HCC

THE PROBLEM

Summing is never just summing

Channel summing looks trivial — add signals, adjust levels, route to outputs. The fundamental problem is phase: two identical signals in phase sum to double the amplitude; the same signals inverted cancel to silence. Real material lives between those extremes, with phase relationships that vary by frequency, change over time and interact across every channel pair.

Standard downmixers ignore all of it, so the result depends entirely on the content. Some material survives; other material suffers catastrophic low-frequency cancellation when out-of-phase surrounds meet the center — bass disappears, dialogue thins out. And clipping compounds the problem: a 5.1 mix with coherent bass across channels can sum 15 dB hotter than any individual channel. Limiters pump; preemptive gain reduction sacrifices loudness.

Bass management concentrates these defects exactly where they are most audible. The usual crossover-and-add approach ignores driver placement, multi-sub interference, and the fact that simply averaging signals into a sub feed does not reflect the acoustic reality. The industry treats this as inherent to summing. It is inherent to phase-ignorant summing.

HOW IT WORKS

How it works

UNDER THE HOOD

Going deeper

HCC brings the correlation engine that powers HSR to the problem of channel summing. Before combining anything, it analyses the phase relationship of every input pair and predicts the consequence of summation — not just whether signals are correlated, but how that correlation translates to summing behavior across the spectrum. Highly correlated signals can sum cleanly if their phase is favorable; weakly correlated ones can still cause damage if the correlation concentrates in critical bands.

From this analysis HCC derives the summing strategy: favorable phase sums directly with proper gain staging; competing peaks are managed across the entire input set rather than channel by channel. Because HCC predicts peak levels before they arrive, gain distributes proactively — no limiter pumping, no preemptive loudness sacrifice. The routing is arbitrary: 7.1 to stereo, 22.2 to 5.1, dozens of channels to a mono confidence feed — the phase protection is automatic.

Bass management is designed in, not bolted on. The crossover is adjustable from 40 to 200 Hz with configurable slope, LFE routes to a dedicated output or sums with the mains, and the crossover region — where long wavelengths turn small timing differences into large phase shifts — receives the same correlation analysis as the rest of the spectrum. Subs and mains stay coherent through the transition.

Everything runs in the time domain — no FFT, no block processing, a few samples of latency — continuously and transparently, replacing the offline measurement and manual phase adjustment that conventional tools require.

AT A GLANCE

At a glance

PARAMETERS

Hands on the algorithm

POSITIONING

Compared to the alternatives

APPLICATIONS

Where it fits