Hi guys. The SHH3580 cable is little different from the SHE3580 one other than that it is one thicker round cable below the Y-split (rather than two thin cables joined together). I don't remember well how the cable was out of the packaging but now it is quite straight and well-behaved. As for microphonics... either I haven't owned a pair with low microphonics or I don't know what you guys are talking about. I thump the cable on any of my phones and I hear a thump... about as loud with any IEM I tried. The difference I believe lies in how easy it is to thump the cable. Here a lightweight cable is less likely to cause hard thumps and the SHE/SHH3580 cable is lightweight. But out of the box they're also curly and springy, which might cause the cable to more easily brush up against stuff and generate microphonics. Here you need to break in the cable... just use the phones regularly and the cable will become straight and well-behaved.
As for the sound signature the SHE3580 is more V-shaped than the SHH3580. The bass and midrange on the SHH3580 are about perfectly balanced with still a tad more treble than the rest of the spectrum... to my ears anyway, but I'm oversensitive to treble. They're certainly not as trebly as say the Etys. Anyway the mids and vocals sound more proper on the SHH3580 than just about any phones I have tried. But their bass is understandably not as impressive as the SHE3580.
Hope that helps!
Cheers mate...helped allot, is the SHE3575 the miced version of the SHE3580?