SPD-11: Triggering from acoustic instruments
The SPD-11 has four external, dual-trigger inputs that allow you to trigger
internal sounds from any Roland dual-trigger pad or acoustic drum trigger. It
is important to note when triggering from acoustic instruments that it may be
necessary to use the AT-4 Acoustic Trigger Interface to increase the signal.
The AT-4 has four inputs/outputs that allow the user to increase the accuracy
of acoustic triggers.
The AT-4 is no longer available from Roland.