Today, around 75% of music is heard via mobile phone and streaming. Enough reason for DALI to consider addressing this target group with high-quality headphones. Their approach is to view the headphones as personal, portable speakers. The first ever headphones of the company – which was founded in 1983 – are the ear-enclosing and sealed IO 6, and its brother IO4, which is identical in construction except for the noise cancelling. The Danes also claim to have discovered that the closed construction causes less sound differences from one wearer to another than open headphones. This construction also made it possible to install particularly large and, from DALI's point of view, better drivers.