Originally Posted by: PoleraIs it fine to run a 4 string bass guitar through a guitar combo? I have a traynor 80 watt with 2 12's in it. The speakers are 70 or 80 watt...i think 70 watt celestions. My primary goal is to play with a drummer...where ive been told that you should have at least 50 watts. My concern really is for the speakers...i dont want to damage them as i suppose the amp can take it.

Well, forget judging things based on wattage specs cause it doesn't really work that way. Basically there's two different ways to blow a speaker.

One is to use too much distortion (which is usually caused by 'clipping' the amp or using too little wattage and trying to turn the amp up past it's designed level.. and yeah, I mean too little. You can blow a 100 watt speaker with a 20 watt amp if you clip it for long enough.). This heats up the coils in the speaker and literally burns them out.
The other way is to physically blow the cone off the speaker by using either too much volume through a speaker not designed for it, or using extremely low frequencies. The cone rattles back and forth so much that it literally blows apart at the seams.

In your case, you're more likely to do it the second way... the small speakers on a guitar amp are not designed to take the low frequencies of a bass guitar. You could get away with it at low volumes, but if you're talking about playing with a band..forget it.