Did they actually sound like that?
Well... it did have an edge but as stated it wasn't really very audible (which kind off surprised me).
Mind you when we played music it was probably playing around 75dB SPL.
When it was mine I had already found that it didn't want to play very loud and got 'rougher' sounding and didn't like an EQ in the bass either.
It was measured at 95dB SPL (measure everything at that SPL to drown outside noises) and I didn't think of it but maybe should have measured it at a (much) lower level.
Perhaps the measurements may have been more favourable.
It should be noted that I experience the same 'problem' with my KSC75.
That doesn't play very loud and sound nice at the same time either BUT it measured 'correctly' at 95dB and sounds good at 'normal' listening levels.
So do the K400 and K500 I measured.