Power Rating

Figure 2: Bass signal with approximated RMS marking / perceived loudness, 12dB crest factor
Solid State Amps
Most solid state amps have a very clean and fast response time in the amplification but also a
sharp edge of going into distortion when reaching its maximum performance level. The distortion
created when the amp reaches its clipping point is very rarely desirable and most users prefer to
not ever experience that in their amp.
With the dynamics of bass signals in mind, this means that a transistor amp has to be able to
cleanly amplify very high peaks in order to reach a decent perceived loudness or power level
without distorting.
Using the 12dB crest factor example again, this means that an 900w amp plays back the
transients or peaks cleanly at its max., but because of the high crest factor of bass signals, the
average loudness and power is more likely to be perceived as 56w by the listener (12dB down
from the peak values) (fig.3).