Pros: Looks sturdy, bass is tight and midrange is lovely
Cons: Hard to get a good seal. A bit-lean sounding. Treble is a bit odd but still good
This headphone has a great neutral sound but I can see many people finding the bass a bit too lean yet not light. This can be due to poor seal which as mentioned earlier is a bit tough to get for some. I personally did find the bass very good however there are times where I feel it’s a bit lacking. But even with the perfect seal, people who are used to big bass and stuff may find this headphone a bit light in the bass.
With a good seal, I think the bass is very good. It’s flat, impactful but not overbearing at all. There’s not much emphasis on the upper bass and lower mids area so it’s not as warm as what I would call as a warm-sounding headphone. Overall midrange sounds natural
The treble part is a bit raised but I didn’t find it bright at all as some would call it. It can be somewhat grainy depending on the audio track that you’re listening to but the mid to upper treble region has good clarity for this type of headphone. Some people also find the treble a bit artificial or indistinct and while I did find it to be true, it isn’t really that much. I think some of the AKG's cans have this same treble signature.
Soundstage is pretty good for a closed back headphone but perhaps this might simply be due to the cups being too big that it creates that perception. Imaging is average and it gets confusing when I listened to some treble-heavy Dream Theater tracks. But the overall dynamics is good.
I only tried Fiio e11 and it did make the bass a tiny bit more prominent but other than there's really not much change.
For full review and some pictures, feel free to read the original review post here: http://www.headphone.ph/akg-k550-review/