How about the Superlux HD662's? Like the 668b but closed. There are three variants
The 662 (red) has deep rich bass
The 662b (grey) is more balanced with lively sound
The 662f (white) has best clarity with a natural sound
So I think the 662f is closest to the 668b with nicer more detailed bass due to the closed design, mids are a bit less recessed, and the isolation is better. For a closed phone they have a really airy open feel to them.
I can't find those on amazon which is where I planned to buy them. I'm a bit weary on buying them on ebay. What would you say about 662f vs HPT990?
Well that solves that now that the superlux's are added I need to compare them, but the HPT990 seems to be what I'm looking for, and cheaper on what I was planning to buy. Only thing is I can't find many reviews on them.