The watts measured amp power are often misunderstood, the common misconception is that wattage has a direct correlation to loudness or volume. Many has beliefs doubling the power output will result in a maximum volume of twice as loud, but actually power output only have a little part in the term of loudness.
Speaker efficiency or commonly known as speaker sensitivity is a measure of speaker’s output, it measures in decibels, with a specified amp power amount. For instance, a speaker efficiency is usually measured with a microphone that connected with a sound level meter and then placed one meter from the speaker. One watt of power is brought to the speaker and the level meter will measures the volume in decibels. The measure of efficiency will come from the the output level. The range of speaker efficiency or sensitivity will be from about 85 dB or very inefficient up to 105 dB or very efficient. To compare it, an 85 dB efficiency rating speaker will need twice from the amp’s power to reach the same volume level as an 88 dB efficiency speaker. And it’s the same as an 88 dB efficiency rating speaker will need 10x more power than a 98 dB efficiency rating to perform at the same level. This means if you’re starting with a 100 watt per channel amp, you’ll need 1000 watts! of power output to double the same volume level.
