Could someone please answer this question for me, in audio how many watts in 100 decibels?

Answer 1

Unfortunately, a deciBel is not a fixed unit, like a watt. A deciBel is a measurement of gain. A dB in itself has no units. It is a ratio of two amounts of the same unit. You need to know what the reference is. Many audio measurements are in relation to SPL, or sound pressure level. From wiki:
When making measurements in air (and other gases), SPL is almost always expressed in decibels compared to a reference sound pressure of 20 µPa, which is usually considered the threshold of human hearing (roughly the sound of a mosquito flying 3 m away). Thus, most measurements of audio equipment will be made relative to this level. However, in other media, such as underwater, a reference level of 1 µPa is more often used. These references are defined in ANSI S1.1-1994. In general, it is necessary to know the reference level when comparing measurements of SPL. The unit dB (SPL) is often abbreviated to just "dB", which gives some the erroneous notion that a dB is an absolute unit by itself.
Manufactures should stop using a dB figure and just give their ratings in RMS watts. Many people consider RMS watts to be the most accurate figure.
Sorry if this sounds like a non-answer, but this is why you can't seem to find anybody with a definite answer. For a level that may help you, 100 dB(spl) is the equivalent of a jackhammer at a distance of 1 meter.
The full article from wiki may help. The link is below.
The second link leads to a dB(spl) table that may also help. I defines 100 dB(spl) as the normal average car or household stereo at full volume.
The answer above isn't valid because it leads to a reference of dBW which is probably not be the reference used in your case.

Answer 2

That will depend on:

The efficiency of the amplifier.
The impedance of the speaker cable.
The efficiency of the speakers.
The impedance of the speakers.
The size of the listening space.
The anechoic ability of the listening space.

Some setups could produce 100dB from about 50 watts watts per channel in a small room. Other setups may need 250 watts per channel.

There is NO real correlation between power output and decibels.

Answer 3

no but you can do it for yourself ...

http://www.ringbell.co.uk/info/dbw.htm