it has consequently had problems with recent peter gabriel records, which are apparently mixed for an audience of elephants (i haven't tried adrian belew yet...), and with a few of my own recordings, which i acknowledge were absurdly built via sample manipulation in cool edit. i took a short piece of music and pitch shifted it in the wave editor to fit specific pitch shifts, like a sampler. this utterly floored the bass frequencies and created a mess, which is intentional, but it means you need to be able to reproduce it or it just crackles and pops.
something like pelican's australasia sounds a little thin, but it does dance music (nin's the perfect drug single) fairly well. it excels at pearl jam, which makes sense - that is the type of music the nad does. ymmv.
i think it's the nad, mostly, and that these speakers have limitations but the nad is struggling nonetheless. i'll have to see how it handles something like "fall of civilizations" coming right from youtube via the chromebook, as there's a direct a/b. the cr-620 drove these speakers quite well. if the nad can't, it's the weak link.