Morbid Angel
Sandoval had never used two bass drums before joining Morbid Angel. He had to practice frequently in order to get his feet up to speed, and recorded the "Altars of Madness" album within only a couple of months of joining Morbid Angel. According to Morbid Angel guitarist Trey Azagthoth, the band would occasionally walk in on Sandoval passed out on the floor in a pool of sweat. After being woken up, he would immediately say, "Time to get back to work!" After mastering the double-bass technique in Morbid Angel, Sandoval also implemented it in Terrorizer's "World Downfall" album when the band briefly re-united to record it.