Hey guess what you call low frequency vibrations

They're funny. Anemic bass if you turn the slider all the way down. They do rumble as advertised, though.

Not at any volume that wouldnt already damage your hearing over extended periods

The regular harms of listening at high volumes apply but from a cursory search there is no harm from infrasound(lower than hearing range, the rumbling advertised) is harmful at low decibel ranges.