Take a look at this..
Perhaps I should take my own medicine and not criticize the noise cancelling PSB M4U2 unit given
that I have not heard it. However, I have yet to hear any noise cancellers (new ATH-ANC9 included)
to rival the sonic goodness of the K550 especially. The Spirit One was a tad too warm to my ears.
But this verdict appears a little silly - a noise canceller scoring 5 from 5 over the K550's more
modest 4/5 followed by the Spirit One's mediocre 3 out of 5.
I'm wondering if this guy would still prefer his PSB unit over any of the flagships to be honest.
Here's the problem - he's a writer for the digital section of a major newspaper in Australia.