Question about high current amps versus "not high current amps"


Recently I read a reply to a post about a certain speaker, and the person who replied typed that (and I am going to paraphrase somewhat) the speaker required a high current amp to perform well and it wasn’t the WPC that was important.

Sorry as I am afraid that these are probably going to be  "audio electrical questions for dummies," but here goes:

I vaguely remember being taught the PIE formula, so I looked it up online for a quick review and if I am understanding it correctly,

P (power/watts) = I (current/amps) x E (electromotive force/voltage) .

My first question would be: if I am understanding that correctly, how can wpc NOT matter since watts are the sum of current x voltage? I mean if you have so many WPC, don’t you then HAVE to have so much current?

My next question would be, if I am understanding PIE correctly, is E/voltage going to be a fixed 110 vac out of the wall, or is that number (E) determined by the transformer (so it would vary by manufacturer) and it is that (different transformers that are used in different amps) going to be the difference between a high and a lower current amp?

Or am I completely off base thinking that P is wpc and P is actually the spec in my owners manual that lists "power consumption as 420 watts operate 10 watts stand by"?

And lastly, what would be an example of a high current amp and what would be an example of a low current amp?

Thanks.

 

immatthewj

@dlevi67 +1

amp does deliver current to speaker-load, AND also dampens / controls current from speaker (inductors and capacitors in passive crossover, inertia generated current by drivers), thus higher current than just driving resistive load output stage is needed. 

@atmasphere ,

One more quick question:

What do you mean specifically when you say ’output devices’? The amp itself or certain components within the amp?

Thanks

@thecarpathian 'Output devices' means components in the output section of the amplifier; usually power transistors mounted to a heatsink. We make both class D amps and tube power amps so in their cases either GaNFETs or power tubes.

@atmasphere

Thanks again.

I don’t know if you get told this often, but I really appreciate that you take the time out from what I’m sure is a full dance card to offer your insight here and to educate.

Some amplifier manufacturers do take current measurements on the outputs of the amp, the Krell I400 has 62 amps of peak current on the output. I'm sure those are taken for only brief milliseconds before the outputs fry.