Forgive me if this is a stupid question, but I want to make sure I'm not going to do something terrible.

If I have a 100 Watt tube amp, how many watts does the cab need to be? Will a 120 watt 2x12 be enough or is there the chance the head can push past 120 and damage the cab somehow?

Pretty much, do I need a 2x12 or a 4x12?
i think the rule is twice as much wattage or was it x1.5 the wattage id be safe though and go with twice
I don't see why it wouldn't be fine, it's 20W of breathing space. If you have your amp on max volume all the time, it could possibly blow a speaker, but then again, you'd also be deaf.
It's rated at 100 before breakup. so 120 would be alright if you never ran it very loud....

keep in mind that the difference between the beginning of breakup and cleans could be like 1 small nudge on the volume. you'd be safer with a 200 watt cab. I'd do 150 at minimum.
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Quote by supersac
i think the rule is twice as much wattage or was it x1.5 the wattage id be safe though and go with twice

yes, i have heard of this 'rule' too, it is far from being completely accurate though. to me, this 'rule' is a good way ensuring flat speaker response across the volume range, good for higher gain or lower tuned music.

for people who want a little 'character' in their speaker response i have know for people to go to such extremes are to run a single greenback with a 50 watt amp. mind you he only ran the amp's power section loud enough to push the speaker just as hard as he wanted, and he was aware it was far from 'safe' and he absolutely expected a shortened speaker life, but he played that amp for over 3 years at gigs and practice without a speaker blowout before finally selling the amp with the G12T-75 safely back in place and keeping the G12M-25 that was still chugging away.

speakers are actually quite generously rated, they take into account that a 35 tube amp cranked all to hell will probably be putting out more than 50 watts so they have built in headroom. but a general rule is that the closer the speaker power handling is to the power output of the amplifier, the more dynamic response and potential 'rounding' or distortion may occur (which some people prefer and other don't).
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Last edited by gumbilicious at Jul 11, 2010,