early_reflector

NODE

Builds a few early reflections from the side component, for the sense of a room with a size.

Parameters

FIELD	WHAT IT DECIDES	RANGE	REQUIRED
damping_hz	Air and wall absorption damping lowpass frequency [Hz] (1000 to 16000 Hz).	1,000 〜 16,000	no
reflections_mix_db	Reflections blend level [dB] (-36.0 to -12.0 dB).	-36 〜 -12	no
room_scale	Room dimension scaling multiplier (0.5 = small intimate room, 2.0 = large concert hall).	0.5 〜 2	no

{
  "damping_hz": 6000,
  "reflections_mix_db": -20,
  "room_scale": 1,
  "type": "early_reflector"
}

How it is computed

S = (L - R) / √2

four taps at 11.3, 17.8, 24.1 and 31.7 ms, scaled by room_scale
each tap is low passed at damping_hz (absorption by walls and ceiling)

R_early = 1.00·tap₁ - 0.80·tap₂ + 0.63·tap₃ - 0.50·tap₄
S_refl  = R_early · 10^(reflections_mix_db / 20)

L_out = L + S_refl              R_out = R - S_refl

The tap times are in prime ratios so the reflections do not line up into a standing pattern, and the signs alternate for the same reason. The blend is differential, so L_out + R_out = L + R: summed to mono, the reflections disappear completely.

Using it

It is not a reverb.
There is no tail and no feedback, only four early reflections. What it adds is the impression of a room having a size, not the sound of a hall.
room_scale moves the walls.
It scales all four delays together, so the pattern stays the same shape and only the size changes. Larger values push the reflections later, which reads as a bigger space.
damping_hz is the surface, not the size.
Lower values make the reflections duller, as a room with soft surfaces would. It does not change where they land in time.
It is mono compatible by construction.
Because the reflections are added differentially, anything summed to mono is exactly what it would have been without the node.