I have read about and talked to people who swear by these little cabs. I will admit, they do sound great, but I just don't think they can handle what I am throwing at them. Today I picked up a PF500, and previously was using an SVT Micro VR head. I could even get the speakers to fart out with the Micro VR head as well, so it's regardless of the head, and if I am running one of the cabs or both. It just seems like when I really hit the strings hard, especially the low E I can get the speakers to distort, and this even happens with low gain settings and the master is not cranked. When I play 'normal' these cabs sound great even when I cranked the master volume, but when you start going at it harder, and/or mixing in some pedals (Boss OC-2, vintage RAT as examples) and then have a hard attack they just don't seem to like that. At one point I thought it might be my pickups, possibly being set too high, etc., but they are fine. Part of me thinks its just the lower frequencies that are making this cab fart out on me, because I can crank it really loud and have no issues, but when I start digging in and playing harder they just seem to fall apart. I have my gain structure set property, dialing it in until the light comes on, then backing it off, and then adjusting the master accordingly to the volume I want. Not sure if there is something else happening, or if I just need a higher wattage cab like the PF cabs.