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The first watts

Okay, let's see if I can ask this question correctly. If you have an class A/B amp and the first 10 Watts is class A and after that it's all class B what happens if you have an inefficient speaker, do the first 10 W get used up real quick so that you're almost never hearing class A amplification, or does it work differently than that?
last_lemming

Showing 2 responses by atmasphere

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atmasphere
12,111 posts
 
^^ For the most part, I would not either, whether the amp is tube or solid state. Due to the rather low efficiency of the speakers, power is likely going to be more important than what class of operation is employed.
atmasphere's avatar
atmasphere
12,111 posts
 
Sound pressure falls off by the square of the distance. By the time you are 9 feet back this can be significant.

2 meters is thus 1/4 the energy. The speakers, once the conversion is done from sensitivity to efficiency, are 84 db 1 watt/1 meter (87 db 2.83V/1 meter and a 4 ohm speaker).

so 1 watt at 2 meters is 78 db. We're a little further back than that of course. 10 watts is 88 db (10x more power). Add 3 db for the other channel. Discount for absorptive materials in the room- carpet, sofa, etc, as well as being further back.

You may assume that the amplifier is making significant class AB power- the 10 watts is likely getting used up pretty quick unless you have a very lively room. However that first 10 watts is likely helping out with low lever detail.
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