I am running a Fender Bassman 400 combo (2001 model?) with the internal speakers and a Carvin BRX 2x10 NEO cab which brings the load to 2ohms. It has been performing well at 2ohms so I just wanted to share for anyone who has this amp and wants to run an ext. cab. because the manual says not to go below 4 ohms. I did add a second fan that pushes air through the rear vent but that was just to be safe. I already played it for an hour or so before adding the fan. Just to note; I play in a "live" environment with a full band but not at a real high level. The volume knob never goes even to half way.