Thread: How do you calculate amplifier output current?

Saw this posted in another thread on the M2.

But, didn't want to derail with a side topic. Pertaining to many high-end loudspeakers and not just Magico.

Often, I'll read posts and or in reviews that a "High Current" amplifier is needed for the respective loudspeaker.

That being said, I'm finding many amplifier manufactures don't post this information publicly.

Short of asking the manufacture directly, is there a formula to determine amplifier current output?

Well it's Ohm's Law, but the easy way is to compare the 8 Ohm power and the 4 Ohm power, if the 4 Ohm power is twice the 8 Ohm power it's a high current amplifier.

Yup, when when I was into the low efficiency speaker/big power amp scene I always looked for an amp that doubled the power from 8 ohms to 4 ohms.

Originally Posted by mdp632

Saw this posted in another thread on the M2.

But, didn't want to derail with a side topic. Pertaining to many high-end loudspeakers and not just Magico.

Often, I'll read posts and or in reviews that a "High Current" amplifier is needed for the respective loudspeaker.

That being said, I'm finding many amplifier manufactures don't post this information publicly.

Short of asking the manufacture directly, is there a formula to determine amplifier current output?

Ohms law as mentioned before , another easy way is look at fuses supplied , most high current amps wont require a fuse change for 4/2 ohm operation, if your are blowing fuses at 4 ohm its most likely, not a high current amplifier.


Regards

Typically a true 89db/W/M speaker played in a moderately sized room at 88dB listening Din will require 200 watts min as not to clip on peaks. That doubles every 3db of lost sensitivity , say 85 db/1/M or lowers if listening levels are lower say 80 db avg din..

Also you need headroom for things like xover insertion , heat soaking of VC , room ambient noise floor , most audiophiles listen to heavily clipped HiFi setups , obvious to those who are sensitive to under powered systems , because of , most select their amps based on clipping
characteristics and less so on drive .


Regards