Applies only to regions that triggered through trigger=release. The volume decrease (in decibels) per seconds after the corresponding attack region was triggered.


<region> sample=pianoA4.wav trigger=attack

<region> sample=keyup_noise.wav trigger=release rt_decay=3

//The sample keyup_noise.wav will play 3db quieter for every second the key has been on.

Range is 0 to 200. In general, higher values mean high decrease of the release sample volume with time, which makes sense for release samples associated with sounds which decay quickly when held. For example, higher piano notes decay much faster than lower ones, so the higher notes will need higher rt_decay values. Release samples for sounds which do not naturally decay, such as organs or guitar feedback, do not need their volume to decrease based on note duration, and can use the default value of 0.

Practical Considerations

In ARIA, extended MIDI CC 151 can be used alongside rt_decay to select different release samples for different time ranges. However, CCs have one value across the entire instrument. CC 151 is time since the last note-on message in seconds. This can give undesired results in arpeggios.

The ARIA extension rt_decayN does not allow different release samples to be selected, but it does allow different values of the volume decrease rate to be used for different time ranges. Unlike CC 151, this is not affected by subsequently played notes.

Name Version Type Default Range Unit
rt_decay SFZ v1 float 0 0 to 200 dB

Category: Performance Parameters, Amplifier