1968 · Acoustic design
Sennheiser dates the launch of its HD 414 open-back headphones to 1968.
The documented innovation concerns enclosure design, not a new recording format.
The HD 414 introduced an open headphone construction in Sennheiser’s product history.
It is a useful historical anchor for understanding open-back designs in today’s catalogue.
The world-first claim is Sennheiser’s account. This entry does not independently resolve all earlier experimental designs.
No cleared reproduction; view the source collection.
manufacturer · Reviewed 2026-09-27 · primary-source
Primary-source confidence means the source directly documents the statement, not that every historical priority or performance claim has been independently established.