User Guide

Chapter 12 Convolution Reverb: Space Designer 173
Setting the Sample Rate
The Sample Rate slider is used to determine the sample rate of an impulse response.
You can choose between the following settings:
 Orig: Space Designer uses the current project sample rate. When loading an impulse
response, Space Designer automatically converts the sample rate of the impulse
response to match the current project sample rate—should it be necessary. As an
example, this allows you to load a 44.1 kHz impulse response into a project running
at 96 kHz, and vice versa.
 /2, /4, /8: These settings are half-divisions of the preceding value—one-half, one-
quarter, one-eighth. As examples:
 If the project sample rate is 96 kHz, the options will be 48 kHz, 24 kHz, and 12 kHz.
 If 44.1 kHz is the project sample rate, the options will be 22.05 kHz, 11.025 kHz, and
5512 Hz.
Changing the sample rate increases (up) or reduces (down) the frequency response
(and length) of the impulse response, and to a degree the overall sound quality of the
reverb. That said, don’t worry too much if the maximum bandwidth of the reverb tail is
reduced to 11.025 kHz when you select a sample rate of 22.05 kHz (half of 44.1 kHz).
Natural room surfaces (concrete and tiles excluded) barely reflect such high
frequencies.
By selecting half the sample rate, the impulse response becomes twice as long. The
highest frequency that can be reverberated will be halved. This results in a behavior
that is much like doubling every dimension of a virtual room (multiplying a room’s
volume by eight).
Another benefit of reducing the sample rate is that processing requires significantly
less CPU power, making half sample rate settings the ideal solution for large, open
spaces.
Activating the Preserve Length button preserves the length of the impulse response
when the sample rate is changed. Manipulating these two parameters as you see fit
can lead to interesting results.
The lower sample rates can also be used for interesting tempo, pitch, and retro-digital
sounding effects.
If running Space Designer in a project that uses a higher sample rate than the impulse
response, you may also want to reduce the impulse response sample rate. Make sure
the Preserve Length function is enabled. This cuts CPU power consumption, without
compromising reverb quality. There is no loss in reverb quality, because the impulse
response will not benefit from the higher project sample rate.