Hello Jeremy,
Most of the time, RPi2 send a continuous beep sound from the I2S DAC output
and is not anymore under control from putty, so, Yes it is RPi2 that
crashes.
Once upon a time, i have xruns errors although jackd is in softmode and
this whatever the buffer size.
I didn't experience problems when the RPi2 was running only
Jackd/jconvolver/Squeezelite (non RT).
I had the problem when running also squeezebox server (RT).
I had similar problems (buffer issues) with RPi2 was running
BruteFIR/Squeezelite/Squeezebox server, both RT and non RT.
I may have forgotten to try Jackd/jconvolver/Squeezelite + Squeezebox
server (non RT).
I will make this and report back.
Thank you,
Jean