I used to have that low end issue too with my tracks in a club, a car, etc. It seems to be the common train of thought that 20-25hz and below is where you should roll off your track, but I find that does very little, personally. Try cutting out all frequencies from 40-45hz and below. You will notice a difference in your sub bass signal, but if you learn to work within that boundary you'll almost never encounter overwhelming muddiness from your sub bass, and you can still get a great amount of low end, just much tighter. I feel like the 20hz and below rule applies more to rock and other genres, electronic music can do with a more drastic cut.

As with all my posts, that's just my opinion, try for yourself.

I travel around fair bit and therefore unfortunately only have a pair of headphones to mix on.

However, I've run into the issue that I can't properly hear the low end of the mix, and the bass or kick often comes out either too muddy or too loud, or too low when played at a club or live venue. I've also noticed in cars that sometimes the bass is at such a frequency that it resonates with the plastic in the car causing it to vibrate.

Just wondering the best way to get the mix to 'work' in the low-end. I've tried using reference tracks and comparing them in Ozone, but my mixes always sound more unrefined, and I've also tried pink noise mixing.

Miles is right--the most ideal mixing environment is a treated room and multiple pairs of good monitors. Headphones don't give you enough stereo information either.

Also, people like to check their mixes in cars, and I think it's overrated and kind of pointless. If you hear something off in a car but not in a studio, the problem is probably the ears.

You gotta use both perspectives, but mostly rely on the monitors.

I pop my headphones on just to get a different perspective and to look at some tiny details. i'd consider it to be a microscope.