Also note that headroom is not necessarily "how much punch is available above maximum rated power". No one (virtually) listens at maximum rated power anyway (well perhaps a few have done so, but speaking realistically it is not an acceptable practice).
Anyway: your *available* headroom is the difference between the actual power level at which you're listening to, compared to the maximum available peak.
20dB, or more, is considered optimal headroom.
10dB is 10 times the power; 20dB is 100 times the power. So if you're listening at 2 watts then you need 200 watts available if you want that 20dB of headroom.
My rig is setup so that it virtually never clips. With high effeciency speakers (105dB SPL @1 watt 1 meter) if I'm listening at 2 watts per channel it's already quite uncomfortably loud for most people. So you need a decent sized amp and high efficiency speakers to stay 100% of out clip.
Anyway: your *available* headroom is the difference between the actual power level at which you're listening to, compared to the maximum available peak.
20dB, or more, is considered optimal headroom.
10dB is 10 times the power; 20dB is 100 times the power. So if you're listening at 2 watts then you need 200 watts available if you want that 20dB of headroom.
My rig is setup so that it virtually never clips. With high effeciency speakers (105dB SPL @1 watt 1 meter) if I'm listening at 2 watts per channel it's already quite uncomfortably loud for most people. So you need a decent sized amp and high efficiency speakers to stay 100% of out clip.