In the 1970s, headphones were used to listen to vinyl records at home. As such, headphone portability has not been an immediate concern for headphone manufacturers. Headphones weigh between 1 and 2 kg. For a sense of relative weight, Beats headphones weigh just 215g.
It was only a matter of time before Sony released the Walkman. This led to a surge in demand for portable his headphones and brought the next turning point in headphone history.