OK here are some pictures of the pair I received. The bluegreen color is very nice (my wife and son both immediately wanted them LOL). The size is actually quite a bit smaller than the K550 and maybe slightly less comfortable for those who love the comfort of the K550 as they achieved the down sizing by making the pads thinner. My ears are medium sized and fit comfortably in the cups but I can see people with larger ears finding these a bit uncomfortable as their ears may touch the sides of the pads. My pair was missing the android cable, so all my testing will be with the apple cable. The cable I do have seems a bit thin but not to bad considering these are designed for portable use. On my Nokia 920 NONE of the buttons work so I will miss the android cable when I test these on the train next week but they work fine on my iPad. I find the cable to by OK but potentially a bit to short. The connector is standard enough that people will be able to get alternative cables from the different cable makers if they need something longer.
I listened to a couple songs and snippets of songs from my Nokia 920 and the sound was a bit thin in the mids but this issue has happened with other IEM's and headphones on my Nokia so I will not use it as my main listening source throughout my impressions and review. When I switched to my iPad mini the sound improved in the mids and sounded more complete or full. Both portable devices needed more volume than my other IEM's and portable headphones, they can drive the K545 OK but they seemed a bit lacking so I tried my new AudioEngine DAC/amp and WOW do they scale well!! Sound improved in all areas substantially! I have to say though these sound a bit brittle right now so I think I will leave them playing music over night when I go to bed and see if they improve with some burn in.
From memory these have a smaller sound stage compared to the K550 but have a similar midrange and treble while having more bass (especially amped). I would say your a bit closer to the stage with these. The change is not so dramatic that if you hated the K550 you will love these (especially if you struggled with the treble) but if you just found the K550 was a bit to bass shy and you can live with a bit smaller sound stage then the K545 will be a pleasant change. The same can be said if you wanted a smaller headphone for portable use. The K545 has a few trade offs to accomplish it's size but if you OK with those trade offs the portability is a welcome change.
I think these will be liked by a lot of AKG lovers and they might sway a few people towards AKG that might not have been fans of the K550 or the Q/K7x series of headphones. Speaking of which I did do a quick comparison between my modded Q701 and these and the Q701 has the larger sound stage placing me several rows further back from the K545. The K545 had much more bass than the Q701 (even modded) and it was a nice full pleasant bass while still having much of the AKG "house sound". So I think these will be an excellent option for commuting and portable situations where more bass will help offset external noise and when you hvae an album that just would be better served with more bass.
I think this is enough for now as I want these to have a chance to settle in before I make many more comments.
Edited by dweaver - 10/25/13 at 5:57pm