UNDERSTANDING: Power calcuations

PS AUDIO / Paul McGowan

One of the most common questions I cannot answer is about matching power amps to Power Plants. It seems such an obvious question and you’d think the answer would be straight forward. But, you’d be incorrect.

The problem with matching power amps to Power Plants happens because we don’t have the complete story. What we’re missing are the speakers and your listening habits. An M1200 monoblock pair is capable of delivering massive amounts of power to speakers, yet in many cases, the pair can be powered with the smallest of our Power Plants, the P3. It all depends on what the amps are being asked to do.

The easiest way to visualize what’s happening is to view the power amp/speaker as a pair. A power-hungry speaker will demand the same amount of wattage from any amp regardless of that amplifier’s rating. And conversely, even power-hungry speakers take less when not being played loudly.

I don’t mean to make this difficult. I bring this up merely to point out that what we might view as a straight forward calculation is, in fact, a bit more involved. If you’re confused, it’s always worth a call to us.

Here’s an easy rule of thumb you can use. If your power amplifier is a standard bias class AB or class D amplifier, and your speaker’s sensitivity hovers close to the 90dB/Watt/meter, then, on average, you’re likely not pushing much more than 100 watts even on peaks. Thus, any of our Power Plants would work just fine for you.

Just remember, amps and speakers should be thought of as pairs.


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