I've known this for ages. This is why I make sure to remember to work on my bass lines on guitar as well as everything else, lol.Don't have to have 4-6 super thick strings to be a bassist... :p
Well....you could run through an octave pedal. In fact, some people play piccolo basses which are tuned high like the bottom 4 strings of a guitar and will use an octave pedal to get that lower range when playing bass lines.