Effects Reference

124 Chapter 11 Convolution Reverb: Space Designer
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.
Similar adjustments can be made while running in Synthesized IR mode. Most typical
reverb sounds don’t feature an excessive amount of high frequency content. If you
were running at 96 kHz, you would need to make use of some deep lowpass filtering to
obtain the mellow frequency response characteristics of many reverb sounds. As a
different approach, you are better served to first reduce the high frequencies by 1/2 or
even 1/4 using the Sample Rate slider, and then apply the lowpass filter. This conserves
a considerable amount of CPU power.
Setting the Length of the Impulse Response
You can use the Length parameter to set the length of the impulse response (sampled
or synthesized).
All envelopes are automatically calculated as a percentage of the overall length, which
means that if this parameter is altered, your envelope curves will stretch or shrink to fit,
thus saving you time and effort.
When using an impulse response file, the Length parameter value cannot exceed the
length of the actual impulse response sample. Longer impulse responses (sampled or
synthesized) place a higher strain on the CPU.