Q: Hi Neil. Some makers are extolling the virtue of seemingly unlimited amplifier power as a requirement for un-restricted system dynamics. Logical or merely smart marketing?

A: Well I suppose it must depend on a number of things. Let's take the things that it depends on. Sound pressure level – that you hear in your head – is governed by the size of the room that you are in, the efficiency of the loudspeakers and the power of the amplifiers. I daresay there are other things, but those are the obvious things which affect the impact that you are going to get.

Now, if you want a very large room, then I think you probably need a very large amplifier. Again the efficiency of loudspeakers varies between perhaps 84db and 95, might be the best for a hifi speaker as opposed to a public address thing. Now that’s an enormous difference in relative power and I can't offhand give you the answer – but I could work it out for you. So just to say you need unlimited power doesn't really make sense. If you have a hugely efficient loudspeaker you can get overwhelming sound with very little power, so these things have to be taken in conjunction.