Peter_s, Ohms law is how an amp's amps would be calculated.
If you know the impedance...and for the case of a simple calculation, it would be the DC resistance, you would use probably 8 ohms. Find out your amp's power supply voltage. This will usually run maybe.....50 volts......I don't think I'll get much argument for that choice..So the calculation would be I=E/R or 50/8 is just over 6 amps. Power, in watts is P=IE or 50*6 or 300+ watts, RMS.
So much for 'hi-current'. This says nothing about a bunch of other factors.
1. What is safe operating range for the output devices of the amp.....mainly referring to SS, here. Heat sinks count!
2. What is the total energy of the amps PS storage? This is usually expressed in 'joules' and can be translated into more familiar measures.
3. What is the speakers capacity? both sensitivity and max power handling count, here.
4. What kind of load is the speaker? Highly inductive or capacitive? Speakers are not correctly represented by 'impedance'..... google 'Power Factor' to see that large phase angles reduce the available power delivered. Better amps are better at this, no question, but in no case can exceed the physics limits.
5. Google 'Smith Chart' for a graphic representation of impedance vs phase angle vs frequency.
The short answer of why you don't see continuous current ratings is that it is a small number, and as we all know, size matters. Amps is inherent in the 'watts' data, anyway.
As for 'burst' or 'short term' capacity, I am open to arguments about how much and how useful. But, Don't forget, even my power hungry Magnepan panels have only a 4 amp fuse, in the mid/tweet, from 600hz up. If my panel can handle 7 or 8 amps, total than how much power is that, really? I stop turning it up when my ears begin to bleed. My 500/side @4ohm ICE amp is way more than enough and since it is dead quiet, huge dynamics, too.
