Ignore the last person.
While it does make the track sound horrible when two low frequencies are played at the same time (it causes the bass to "warble", and it makes said bass indistinguishable to other said bass), it doesn't make the track distort.
What does make the track distort however, is failing to compress your song.
Let's say that your track is like a glass. It starts out empty, and you add instruments and different elements to the track (essentially filling the glass). But let's say you add too much, and it's all too loud. Well then you've filled the glass too much and it's spilling everywhere (also known as "distortion"). So, how do you fix this?
Turn what you want to be quiet down, and what you want to be "loud" at mid-volume. Turn things up and down accordingly, but try not to max out the volume/EQ of anything.
So, there. We've got a nicely EQed track, and there's no liquid outside of the glass. But, on a different system, this would still overflow if you turned it up! Do you know why?
There's no lid on the glass. And when there's no lid, sometimes the liquid will stay in, but shake it too much and it'll all flood out. Something we don't want. So, put the "lid" on the "glass" by individually compressing the things that need to be compressed (the loud things). You can do this by putting a compressor on every loud instrument, and fiddling with the highs and lows of that particular instrument (while putting a limiter on it, of course) using the Multiband compressor.
So, keep the lid on that glass, mmk? Keep this up man, and I'm sure in another week or two's time, I'll be asking YOU for advice :)
Keep it easy bro;
-Zenon