Do you want the samples to start at the same time, and then restart together when the longer one finishes, or do you want them to be altered to take the same time to complete?
In the former case, play each one in a separate live_loop and sync the shorter one to the start of the longer loop. In the second case use beat_stretch option to alter the rate so that it occupies a known number of beats. eg
method 1 shorter loop synced to start of longer loop
live_loop :short do
sync :long #waits for loop_breakbeat to restart
sample :loop_amen
t=sample_duration :loop_amen
puts "duration loop_amen is #{t}"
#no need for sleep because of sync
end
live_loop :long,delay: 0.001 do #:delay makes sure short loop is primed before :long starts first time
sample :loop_breakbeat,amp: 2
t=sample_duration :loop_breakbeat
puts "duration loop_breakbeat is #{t}"
sleep t
end
method 2 both loops adjusted to last 2 beats using beat_stretch option
live_loop :a do
sample :loop_amen ,beat_stretch: 2
puts "loop_amen"
sleep 2
end
live_loop :b do
puts "loop_breakbeat"
sample :loop_breakbeat,beat_stretch: 2
sleep 2
end