Amplifier current vrs watts; why is current more important?

Here is proof to what I posted above, and the speaker load in both instances, is a very easy to drive Kantor simulated speaker load, a bad load will look far worse.

Look at the black wavy line.

This is the well known Prima Luna Prologue Premium 25w tube amp with very questionable current.

8ohm tap + - 7db!! frequency response, "a tone control"
https://www.stereophile.com/images/1116PLPPfig01.jpg

4ohm tap+ - 5db!! frequency response "still a tone control"
https://www.stereophile.com/images/612PPPfig01.jpg

Here is the Pass XA25 25watter with far more current that the PL above, it’s +- 0.1db frequency response. Virtually flat as it should be!!!
https://www.stereophile.com/images/218PXA25fig1.jpg

Cheers George

viridian
So I do it backwards and choose the amp first.

That’s fine, so long as the speaker then chosen doesn’t cause that amp to become a "tone control"
To me I would think in that easy "Kantor Simulated Speaker Load" graphs I posted above, that Stereophile uses, that +- 1 or 2db deviation from flat would be acceptable.

That means easier loads than the "Kantor" horns, JBL ect the amp would be almost flat and on harder to drive than the "Kator load" the deviation would still be just acceptable at +-3db deviation from flat.
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Cheers George

A speaker is an INDUCTIVE load.  What that means is that it proportionally resists the rise of voltage across it.  In Calculus, the voltage across an inductor is given as:

V = L x di / dt

L: inductance in henries and di / dt is the rate of change of current thru it.

When transients occur, the amp has to overcome the resistance of the speaker to increasing the voltage across it.  That is why it is difficult to drive inductive loads.  To be able to do that, amp has to be able to deliver loads of current.

Electronics 101: inductive loads.

PS: Music is not a straight sinusoid signal.  It is a MESS of transient signals.  A piano for example is almost like a steep 90 degree rise in signal.  To faithfully reproduce it, an amp must be able to supply LOTS of transient current, hence the need for an ENORMOUS power supply.

Having said that electrostatic speakers a different ball game.  They are capacitive loads.  Combine different frequencies and it is a miracle that modern amps actually work :-)