[Kent0]

Yes, the pads are replaceable.

No, 2X the price won't get you 200% the performance,  it will get you a more comfortable headphone and a different sound, but still in the same league.  The best bang for your buck is definitely the HD518, though if you don't like its distinctive signature, it isn't a good buy. Right now on Amazon at 99$, the HD558 is (imo) the best buy in the lineup.

Sure, I'll check the HD 558. If I can find a good price. As headphones from where I am are not cheap. And last question. How does that HD 558 compare to the 595? As they are very similar. Sorry for the tons of questioning.

 

[Music Alchemist]

I would not describe the HD 558 as thick. More like slightly warm, yet crisp, if that makes sense.

 

[Rem0o]

Sure, I'll check the HD 558. If I can find a good price. As headphones from where I am are not cheap. And last question. How does that HD 558 compare to the 595? As they are very similar. Sorry for the tons of questioning.

As I said earlier, I haven't heard any HD5x5, so I wont comment on that comparison.

 

[Sefelt103]

I don't think Sennheiser's HD555 and certainly not HD580/600 are what you are looking for. Sennheiser's are fairly neutral headphones and I wouldn't describe them as thick sounding, perhaps slighly warm but not much. The HD595 are a bit more forward and colourful as well as being elegantly dark headphones. Other manufactures like Sony, Grado will have much more colour than Sennheiser.