I was looking for this old Eno quote about how the closest thing to ambient music was heavy metal, on account of the engulfing, sound-for-sound's-sake quality both genres share. And found this from the Daily Telegraph, November 17 1995:

.... The soft-spoken musical pioneer has more predictions for the future. "Ambient is closer to heavy metal than anything else. Because it's to do with immersion and so is heavy metal. It's obvious to me that the next step is going to be something like metal ambient, some extremely harsh, hostile but intriguing sonic environment."

But I'm almost positive this is Eno recycling one of his old licks, and that he had made this heavy metal/ambient connection much earlier--in the Eighties. Because far from being a soothsayer with this November 1995 utterance, he's lagging a bit: Earth's second album would have been out a couple of years by this point (although that seemed like "ambient grunge" at the time) and the Isolationism compilation had recently come out I think and if I remember right had some things by Final and Lull on it, i.e. metalheads (Godflesh's Justin Broadrick and Napalm Death/Scorn's Mick Harris respectively) doing the ambient noir deathscape thing.

So does anyone recall when and where he first made that metal/ambient connection?