It might be possible to damage the 800 watt cab you mentioned if you run the amp with all of the knobs all the way up, so watt ratings are a guideline not an absolute limit. You could probably use any of the cabs you mentioned (400, 600 or 800 watt rating) with no problems if you pay attention to the cab while playing and not allow it to fart out or sound like it is laboring to keep up with your needs. The most likely to be over powered is obviously the one with the 400 watt rating but again if it is loud enough without laboring you should be fine. I use a fridge with a 300 watt rating powered by my 1400 watt SVT 4 Pro and have never broken it in 5 years now.
You can clearly hear speakers dying (in most cabs, direct radiator designs yes/horn loaded designs not so much) when they are being over powered so listen while you play...
The laws of acoustics don't bow to opinion - Bill Fitzmaurice
Last edited by bassmeknik : 03-26-2013 at 10:41 AM.