dont spend several hours tracking something and then glance at your stereo (which your computer’s sound goes through) to see that BASS BOOST and DSC: POP are switched on.
especially when you’re tracking for a beatbattle.
Been there… done that… bought the T-shirt and so on… 
I often turn down the bass to minimum when watching movies cause my neighbours would probably freak out otherwise. It has happened quite a few times that I forget this later when starting up Renoise. The last song I actually finished was also indeed finished and rendered when I realized this So it was the other way around as in your case… the song turned out to be pretty distorted.
oh no, that’s even worse… 
anyway, i found a way to fix my problem. i won’t say how though, the compo entries are supposed to be anonymous 
thing is, i hate those stereo settings and never use them. and whenever i see my brother using them (especially when he’s tracking) i always tell him not to. but this time it was me who turned them on, not him. there’s something about the way the tool album ‘lateralus’ is recorded that makes it sound horribly tinny on my (admittedly mediocre) stereo. turning those settings on helps a lot…
so i’ve no-one but myself to blame 
ROFL 
then you try to repair yer work with an EQ and it still sucks 