Ohmage Question regards 2.67 & 2..

[Old Ozzie Guy]

Hi all, I have a question regarding output power and ohmage.

With a 500 watt class D amp , with a 2 ohm minimum, what would amp output into 2.67 ohms, still 500 watts, or would there b a slight reduction? Am I confusing Class D performance with Class A/B, or am I just confused?

Any thoughts b much appreciated.

[nikon F]

very slightly less , but not enough to worry about,. impedance will vary anyway i believe.

[fretmeister]

So little of a difference you’d need scientific instruments to realise it.

[Old Ozzie Guy]

Thanks, I wasn't sure, been using valve gear for gtr since 70s..( for 6str gtr), and  now back playing bass, so learning about class D..., Just got a Darkglass micrtubes 500, want to run 3 X 8ohm boxs .

[Woodinblack]

As people said these things aren't exact, but it would be a fair bit less.

 

500W into 2R means that the voltage is 31.6V and the current is 15.8A. In a transistor based amp (a/b/d - doesn't matter), the amplifier is providing the voltage and the current is just a function of the resistance, so for 2.67R that means you are using 11.8A which gives you a power output of 374.5W

 

In a valve amp, it would be the same power output, due to the transformer 

[Old Ozzie Guy]

Thanks, that has been my experience with old AB ...I guessed at 25% drop in output..500 down to 375.. I was close....cheers

 

[TimR]

I wouldn't worry too much about power output. If you have 3 cabinets you'll get a fair increase in volume from having more speakers.