The VLE on the Markbass amp is a Low Pass Filter. However, if you're wanting a beefier sound then the Moog LPF adds a shedload of depth to the sound.
I've went for a more Drum n, Bass/Dubstep sound & found that Flatwound strings, octave, dirt, LPF & a little chorus gets me what I want. But it's all about messing with gear (be that bass, amp, pedals or all them) until you get what you're after.