Youtube user DivKidMusic has posted this comparisson of 5 low pass filters. As he says its more of a listening test to find out which you might prefer than a full blind test.
"I have 5 low pass filters, let's do a blind test and video to show how they differ".
The AniModule - SOB, Mutable Instruments - Ripples, Erica - Polivoks VCF, Malekko / Wiard - Borg 2 and Livewire Frequensteiner. They all just have a single saw wave input.
He's also set up a user poll on the excellent Muffwiggler forum, You'll need to register to view that.
So, did you guess which was which?
Volca Sample active MIDI cable changes everything
Live sax processing, sequencing and modular all together