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  3. 175990-102842

Current Questions

More and more, I see the word “current” in audio reviews. The reviewers warn me that I’ll “need lots of current” for a given speaker but they don’t explain exactly what it is I need or how many “lots” is. I’ve looked at a few “Electronics For Dummies”-type sites but I’m still confused. A few questions:

 

—What is current?

 

—When someone writes, “These speakers need a lot of current,” what do they mean? Is sensitivity involved? Impedance?

 

—On the amplifier end, what specification measures current?

 

—Are there subjective considerations at work in that spec? The number of watts doesn’t tell me everything about loud an amplifier sounds. Does the number of [whatever measures current] similarly leave things unexplained?

 

—Everyone asks, “How many watts?” No one asks, “How much current?” Is it really so important?

paul6001
terry9
2,322 posts
 

@daledeee1 "Why do all or most electrical items use the letter "A" example: 1.2A"

A for amps. Amp for Ampere.

 

holmz's avatar
holmz
2,328 posts
 

A for amps. Amp for Ampere

itsjustme
681 posts
 

you need to watch "the story of electricity" done by, i believe channel 5 in the UK with a physics professor from U sussex. Superb and answers many fundamental questions.

And as both an engineer, and also one who's stupid enough to have spent a lot of time designing high end stuff commercially (its a terrible way to make money) -my advice is absolutely learn some basic engineering, but really dont worry about it.  In the end all this suff is a trade off of cost/size/heat.  What is important is that inefficient or lower impedance speakers, which demand lots of those current things (amps, or getting really techie, movement in electrical charge) need beefy amps.

 

Beware a little knowledge.  Continuosu current emands serious beef, weight, size etc. But most music is not continuous - it has a peak:average ratio of about 10X. So what one really needs is the ability to seamlessly burst. The burst is actualyl voltage, but (because I=V/R remember) if it doesnt have the current ot back up its "ask",the burst will be truncated into some pathetic shadow of its self.  Flabby at best, loss of dynamics, etc.  Distortion of one kind or another.

So given how inter-related these thigns are either learn it really really well, or dont assume you can make major inferences.

 

Sorry: complex.

 

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