For fans of: The REAL history of the synthesizer, computer-music, and far-out sounds generally.
What they're saying: Well, Pitchfork named Expanding Universe the #12 ambient album of all-time, calling it “approachable, expressive, and deeply enjoyable”. And in Resident Advisor’s loving review of both reissues, they call Unseen Worlds “dark matter of Spiegel's universe”.
What we say: Both originally released in the earliest 80s, Unseen Worlds is the creepier, gothier one, Expanding Universe is the alien-loving-giant-cosmic-brain-drone one. Both are essential documents in experiments with electronic sound.
Further listening: How about get to know Laurie: