Head and Cab tolerances

[bassclef216]

Scenario:
- I have a bass head that delivers 250 watts @ 4 ohms.
- I have a bass cab that is rated at 500 watts RMS @ 4 ohms

Without getting crazy technical, should I be able to run the amp full bore (wide open) 10 on the volume without damaging the cabinet?

[Bass_Pounder]

No

Depending on how you EQ, you could cause physical damage to the cones at way below the "thermal" wattage rating.

[BurningSkies]

No. ALWAYS use your ears to hear when your bass cab starts complaining. How people rate cabs and heads varies, the numbers themselves are usually suspect, and don't refer to real world usage as much as a measuring standard.

An amp is capable of outputting levels much higher than rated, and many cabs list a speaker thermal handling rating rather than anything to do with excursion based upon EQ.

[bassclef216]

So then the RMS wattage number are just a very rough guidline on where to start while pairing cabs to heads? After that you just have to guess and listen to when the cab might be in trouble?

[BurningSkies]

Originally Posted by bassclef216

So then the RMS wattage number are just a very rough guidline on where to start while pairing cabs to heads? After that you just have to guess and listen to when the cab might be in trouble?

Exactly. The ratings you see are very rough estimations of what you can expect from that gear. If you push the lows in your sound, you can expect your amp to run out of steam earlier and your cab to start distorting and 'getting into trouble' at less volume than if you have say, a mid forward sound.

Also, if you're planning on turning your amp all the way up, you should consider buying a more powerful amplifier... And again, LISTEN to what your speakers are telling you. Are you getting breakup and distortion or dreaded 'farting'? Your cab is telling you that you're feeding it more than it can handle.

Unfortunately amps and cabs are not like Geranimals.

http://en.wikipedia.org/wiki/Garanimals

[JTE]

Originally Posted by bassclef216

So then the RMS wattage number are just a very rough guidline on where to start while pairing cabs to heads? After that you just have to guess and listen to when the cab might be in trouble?

I don't even think it's a rough guideline. I've pretty much ignored power rating specs on speakers because they're about the most useless spec anyone publishes. The other common specs COULD mean something if everyone measured everything the same way every time, but they don't so the only specs to which I pay attention are the dimensions and the weight.

EVERYTHING else is measured by MY ears when I'm playing MY bass through MY amp.

John