Was supposed to build a mallet but stumbled onto this accidently ,  Its a crude thunder effect made with two layers , its very crude liked  it so much, This needs a bit of work it could be much simpler the trick is playing with Release 1  time  ,Level  and Release 2 Time and ranging the sounds also filters LPF3 and HPF I've found does the trick as well keep the tones  very short  like a pluck.  As a note Release 2 time  maintains the tail of the sound.