I bought these and a pair of AF45s on and immediately put the Af45s back in the box after hearing these. I bought a pair of NAD viso50's and find these are much more versatile and forgiving when paired with varied sources. Whereas the Polks sound very pleasant when paired with laptop, streaming spotify premium from my HTC M8 or even save me battery life while sounding just as good through the Fiio Q1 I just bought, The NAD's seem to be very revealing of whatever electronics you hook them up to by comparison. Reproduction is probably 90% of the NADs...