In 1985, Soundgarden was a recently formed three-piece band with Chris Cornell on vocals and drums, Kim Thayil on guitar, and Hiro Yamamoto on bass guitar. The band enlisted Sundquist as their drummer so Cornell could focus on the vocals. They traveled around playing various gigs with this lineup for about a year. They then recorded three songs for a C/Z Records compilation album of grunge music by Soundgarden and five other bands, which was called Deep Six and was released in March 1986. This album contains the only recorded Soundgarden material with Sundquist.
Also in 1986, Sundquist, who by that point had a wife and a child, decided to back out of the band and pursue a normal family life. They were briefly left without a drummer until they were able to lure Skin Yard drummer Matt Cameron away from his band. Cameron stayed with Soundgarden until the entire band broke up in 1997 and rejoined the band in 2010 when they reunited.