Soundgarden will be diving back into the Superunknown this spring with multi-disc, rarities-packed special editions of their 1994 album. In celebration of the record's 20th anniversary, the band have planned two deluxe reissues and a vinyl edition of the LP, which debuted at Number One when it was originally released, for a June 3rd release. Each disc will contain demos and recordings from rehearsals, many of which have never been released.