I’ve gotten conflicting advice. One review tells me that a 50Wpc amplifier will be enough power for most people. Another review says that I should look for an amplifier that delivers at least 100Wpc just to be safe. What gives?
I’ll preface this answer with an explanation of amplifier power versus output level For every 3dB increase in output level from your speakers you need to double amplifier power. That means a 100W amplifier will only play 3dB louder than a 50W one, a 200W amplifier will play 3dB louder than a 100W one, and a 400W amplifier will only play 3dB louder than a 200W one! As you can see, you need plenty of power if you really want to crank things up, but not everyone wants to.
How much power you need depends mostly on the sensitivity of the speakers, the size of the room, and how loud you like to play your music. For most people, an amplifier that delivers 50Wpc into 8 ohms will suffice. I’m basing that on the assumption that most people don’t have really big rooms and they don’t play their systems extremely loud. For those that do like to play louder, or have a larger room, or have insensitive speakers, something in excess of 100Wpc might be more suitable. That extra 50W will allow 3dB more output, but it will also give you more headroom, meaning a larger margin of safety before the amplifier hits its limits and is driven into clipping and starts distorting badly. Perhaps that's what the reviewer who said "to be safe" meant. In the end, though, 50Wpc might be more than sufficient, since it depends mostly on the setup and the listening habits of the listener. Therefore, both of those reviews you read might be right. . . . Doug Schneider