well 4 ohms is gonna draw less power than running at 1 ohms,but i mean it takes less power per watt when your running at 1 ohm,if you understand what im trying to say
well power supply efficiency is also a factor. most manufacturers print an efficiency at 82% o whatever, that is at 4 or 8 ohm load and with a very very regulated power supply. higher the power the better the efficiency and the lower the load the lower efficiency
" amps become more efficient the lower the load goes "
Wrong
" it takes less power per watt when your running at 1 ohm "
Wrong again
" I thought it was higher efficiency at higher loads, like 4ohm is more efficient than 1ohm "
Correct
To answer the original question, efficiency ratings are almost always at 4 ohm unless it says otherwise. How much the efficiency drops as the impedance is lowered depends on the amp, but on average, 2 ohm efficiency is ~10% less than 4 ohm, and 1 ohm is about 10% less than 2 ohm.
For example, if an amp is rated 85% efficiency, it would likely be ~75% at 2 ohm and ~65% at 1 ohm. That is NOT an accurate measurement, just an estimate.
I was wrong above. The higher the ohm, the less resistance. The lower the ohm load, the more resistance. Basically, A lower ohm load will cause a larger amperage draw. More amps means more voltage drops. More voltage drops means less efficient.
So more ohms = less resistance? It's counter intuitive... I know you guys must be right, you usually are, but I can not understand how 4 ohms would allow more current to pass through than 1 ohm when you might get say 800 watts out of 4 ohms and 1600 out of 1 ohm with the same voltage being supplied. I understand that you would lose more power to heat running at 1 ohm but does the increase in output count for nothing?
Maybe I don't fully understand what efficiency is defined to be.
the higher the load the easier for the amp to handle... means better efficiency.. best thd ratings... and best cooling and less tress on the amp than when used on lower impedances...
audiophiles always use higher impedance loads on their system. most of them run high quality mono class amps at at 8 ohms
