How To Protect from UNDER Powering Damage?
Any speaker can be damaged with too much power. Low Power Can Damage all speakers, but especially High Frequency Units. A loudspeaker system capable of handling 100 watts should have a high frequency unit capable of handling 10 watts. If the high frequency unit is rated at 20 watts there should be a 100% safety factor. Using an lower powered amp can cause distortion which can damage a high frequency driver.
To protect your high frequency drivers: 1) do not drive the amplifier into clipping, 2) do not make or break speaker connections while the amplifier is operating, 3) volume controls should be turned down before powering amp, 4) guard against power surges.