User Guide

Waves IR-1 software guide page 28
LOW FREQUENCY DAMPING RATIO: Range: 0.10 to 2.00; Default: 1.00
This control defines the ratio by which the frequencies below the Low Damping Frequency
will decay in relation to IRs general Reverb Time. Values of less than 1.00 are shorter than
the IRs Reverb Time, and values greater than 1.00 are longer than the IRs Reverb Time.
LOW DAMPING FREQUENCY: Range: 16Hz to 1600Hz; Default: 600Hz
This defines the frequency below which the Reverb time is controlled by the Low
Damping Ratio Control.
HI FREQUENCY DAMPING RATIO: Range: 0.10 to 2.00; Default: 1.00
This defines the ratio by which the frequencies above the Hi Damp Frequency will decay in
relation to the IRs Reverb Time. Values of less than 1.00 are shorter than the IRs Reverb
Time, and values greater than 1.00 are longer.
HI DAMPING FREQUENCY: Range: 1000Hz to 21000Hz; Default: 2500Hz
This defines the frequency above which the Reverb time is controlled by the Hi
Damping Ratio Control.
MORE ABOUT REVERB DAMPING
Damping is the frequency response of a room’s reverberation. This information is captured
in the Impulse Response. The total decay time of a room might be 2 seconds, but high
frequencies might have a decay time of 1 second. In this case, the high frequencies would
have one-half the total time. This can be expressed as a Ratio. For this example, the HF
ratio would be 0.5 (that is, 2 seconds multiplied by 0.5 = 1 second). A room with hard,
reflective walls, such as a bathroom with tiles, can have a HF ratio greater than 1, giving
longer decay times (and a very bright sound).
HF damping is the reduction of reverberation time at high frequencies due to absorption
of high frequencies by the air and absorption in the walls. Generally speaking, this high
frequency reduction in reverberation time is necessary to avoid a very splashy or sibilant
sound. The degree of HF damping actually changes in real rooms according to
furnishings, audience size, air temperature and humidity.
• Typical HF damping frequencies may be between 4 and 7 kHz.
• Very dry air increases HF damping. Stone walls, such as in many churches, give less HF
damping than do wooden or furnished rooms.