I'm back to report my findings with new impedance adapters. Over the past few weeks I have been using the 75ohm adapter, and while it really brings out the energy and details that I thought were lacking with the original sound signature out of the iPhone 6 HO, it thinned the bass out a little too much for my liking and the treble was a little too peaky, sometimes reaching screechy and sibilant.
I just received a 22ohm adapter from the same vendor on eBay and am happy to say that this is a great compromise between the iP6HO and the 75ohm adapter. Really great PRaT, imaging, details and oh wow the mid-highs just becomes the star of the show without losing any of the original great qualities such as timbre and details. The bass becomes thinner, but not to the same extent as with the 75ohm, yet the augmentation of the mid-highs is just perfect. Not too sibilant, yet just enough energy, speed and sparkle.
I simply can't go back to listening to the Andromedas right out of the iP6. It sounds veiled and even muddy in comparison. Give it a go, it's only US$18.
http://www.ebay.com.au/itm/301984920451?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT