This video shows how to optimize the last shockwave, using only visual cues (no need to count anything in your head) :D

NOTES: (these are the important things I do in the video)

• jump the farthest possible, and immediately stop after the roll
• wait for the shockwave to pass and look to the upper-right side
• after the barrel flies, look for the metal sheet that hits the machinery
• just as the metal sheet hits, start running (without jumping)
• perform a last jump as farther as possible, to get a faster descent