Watts and power


Can somebody break it down in layman's terms for me? Why is it that sometimes an amp that has a high watt rating (like, say, a lot of class D amps do) don't seem to always have the balls that much lower rated A or AB amps do? I have heard some people say, "It's not the watts, it's the power supply." Are they talking about big honkin' toroidal transformers? I know opinions vary on a speaker like, say, Magnepans - Maggies love power, right? A lot of people caution against using class D amps to drive them and then will turn around and say that a receiver like the Outlaw RR2160 (rated at 110 watts into 8 ohms) drives Maggies really well! I'm not really asking about differences between Class D, A, or AB so much as I am asking about how can you tell the POWER an amp has from the specs? 
redstarwraith
I will guarantee something you have not done ... listen to the Alexia with the Behringer. They may not be fancy, and they may not be what we traditionally think of as "hi-fi" but they are designed to drive loads every bit as harsh as the Alexia, and to do it continuously in harsh environments.


georgehifi6,476 posts12-22-2019 2:33pm

Like said listen to the Alexia driver by the 3000w Behringer then with the 25w ML2's  

I don’t care for what you say, you need amps that can almost double down for each halving of impedance, not ones that actually halve their wattage and go backwards!! with current sag limiting into hard loads.

Next you’ll be telling me that a 100w OTL tube amp will drive the Alexia better than the 25w ML2.

You stick with your $400 3000w Class-D’s, and go spruik your views on a PA sites instead where you’ll make a dent
Georgehifi,

Here is the difference between me and you. Your posts are all conjecture and hand-waving. Conjecture and hand waving is ..... well just that.
Again, let's look at facts:
  • 1500 watts into 2 ohms is 27 amps
  • 100 watts into 2 ohms is 7 amps
  • Maximum dissipation in a LINEAR amplifier with a real speaker load DOES NOT happen at the spot on the speaker impedance curve where the current delivery is highest.
  • Class-D is not impacted by phase w.r.t. power delivery in the same way a linear amplifier is, either in device dissipation or power supply loading.
  • Other than knowing an amplifier can deliver 100 watts into 2 ohms, you have no data that shows the power supply is any more capable of supporting continuous additional power delivery and the dissipation peak of the speaker load
  • You have not heard the Alexia with the Behringer, but you are making many claims that you don't have the requisite data to support.
  • You are deflecting bringing up OTL amplifiers
  • There are many reasons why power may not double with every 1/2ing of the impedance, and without knowing what that reason is, you can't made factual conclusions about an amplifier beyond that it will clip at a given wattage and load impedance (as stated in the specs). If the 2 ohm wattage is stated (and distortion components), and given that impedance doesn't drop below 2 ohms for almost all speakers, then beyond knowing where clipping will occur for 2 amplifiers, you really don't know much else. Any other conclusion you arrive at is purely assumption.