Summary: HD558 offers balanced overall package for an entry level studio monitor.
Pros: Exceptional comfort level and practically no clamp force and headband offers good padding so you won't feel the headphone weight on you much. It has a rather bright sound which is clear and detailed. Clarity is nice and good sound stage for an open headphone.
Cons: Bassheads may find the bass to be lacking here. A headphone amp is recommended to correct this issue
Summary: My chain: Lossless -> Foobar 2k -> HifimeDIY Sabre DAC -> E11
The HD558 are doing it for me right now. I was not blown away, but they really don't do anything wrong. The bass is not boomy but does bleed a tad, not ideal for classical but it's not hugely problematic.
The mids are nice. Never overly resonant, just enough bite to give realism but not intrusive. Imaging is very nice, but transients are a little weak.
Pros: Mostly neutral tonality, quality timber meets or exceeds expectations for the price, good presence across the spectrum, great all-rounders
Cons: Sennheiser veil, bass can bleed a little and doesn't go all the way down, mids not always as forward as I would like ideally
Summary: When I first listened to this headphone I was disapointed with how it sounds. Frequencies close to 150Hz are elevated and the trebles are damped. That results in a boomy sound as if I had a piece of thick cloth between my ears and the headphone. I removed the pieces of foam inside of the HD 558 but it improved the sound only marginally.
However once I played around with the bass and treble knob the sound of the HD 558 became more pleasing to my ears.
Pros: Comfortable, solid look and feel, detachable one sided cable, replaceable cushions, low impedance and high efficiency.
Cons: Boomy sounding, cable too long and ends in a 6,35mm plug, rediculous 3,5mm adapter.