10.6

273Logic Pro Effects
Plates, digital reverb effects, and convolution reverb
The first form of reverb used in music production was actually a purpose-built room
with hard surfaces, called an echo chamber. It was used to add echoes to the signal.
Mechanical devices, including metal plates and springs, were also used to add
reverberation to the output of musical instruments and microphones.
Digital recording introduced digital reverb effects, which consist of thousands of delays
of varying lengths and intensities. The time differences between the original signal and
the arrival of the early reflections can be adjusted by a parameter known as predelay.
The average number of reflections in a given period of time is determined by the density
parameter. The regularity or irregularity of the density is controlled with the diffusion
parameter. Included among the digital reverbs are the unique Logic Pro EnVerb and
ChromaVerb. See Logic Pro ChromaVerb overview.
Computers make it possible to sample and analyze the reverb characteristics of real
spaces, using convolution reverbs. These room characteristic sample recordings are
known as impulse responses.
Convolution reverbs work by convolving (combining) an audio signal with the impulse
response recording of reverb characteristics for a given space. See Logic Pro Space
Designer overview.
ChromaVerb
Logic Pro ChromaVerb overview
ChromaVerb features fourteen discrete room type algorithms.
The fundamental approach behind ChromaVerb diverges from other methods of reverb
creation. It is based on the principle of a circular structure in which the sound is gradually
absorbed, much like in a real room. The absorption characteristics are dependent on the
chosen room type and reverb parameter settings.
Each room type offers a unique tonal color, ranging from dense rooms to wide spaces and
large halls.