Most teenagers and young adults can hear 20kHz. That is why CDs are made to play up to 20kHz.
Old people can hear up to 10kHz.
People who worked with loud noises for many years hear everything like an AM radio or like a telephone.
Home speakers have a sensitivity of about 88db/1W/1m.
You don't wear speakers on your ears. The speakers play into a room and the loudness at your listening position is much less than it is close to the speakers. The 1W into two speakers produces 91dB at 1m and only 79dB at 4m.
100W RMS would be for the loudest peaks of music, the beat that you can feel. At a listening position the occasional peaks of 100W are not too loud (99dB). The average power is about 10W RMS which is not too loud (89dB).