Hi! Bear in mind that I just recently got a Virus so I'm still not 100% familiar with the parameters.
The manual states that the "Split" mode will route Osc 1 and the sub through Filter 1 and Osc2+Noise through Filter 2. However, when using two hypersaw oscillators and split mode, I seem to be able to hear the Sub through both Filter 1 and Filter 2. The sub isn't coming from just one speaker, and also, it's audible even when the filter balance slider is at the extreme right (which should only allow me to hear Filter 2, ie. just Osc 2 and the noise generator).
This is a good thing I suppose. If the sub was only sounding from one speaker it would throw the balance off.. but I would still like to know what's going on.