What affect does amperage have on speakers? (1 Viewer)

[Joe Bauman]

I see that power amps vary on the maximum amperage they put out to a speaker. How does a lower rating, say 45, compare to a higher rating such as 65 per channel? Is an amp that puts out more amperage better? Also, what would constitute a negligible difference? Thanks.

 

[Saurav]

Also, what would constitute a negligible difference?

Good question. 45 vs. 65 isn't really negligible. However, you also have to figure out how much you need. Here's a rough calculation (and someone please correct me if I do this wrong):

Let's say your room/speaker sensitivity/volume preference results in your amp needing to send 100W peaks to your speakers. If you have 8 ohm speakers, a 100W peak translates to 3 or 4 amps? P = I^2 * R, right? A 200W peak with a 4 ohm speaker gives you 7 amps. And with any reasonably sensitive speakers, 200W is an insane amount of SPL.

So... if you multiply by the number of channels, 65 looks better than 45. However, if you had to choose between 65 and 100, I don't see why you'd ever need a 100A current capacity.

This is all off the cuff, of course.