MISSION POSSIBLE

We listen to the iconic Mission 770 speakers, both old and new. 45 years on, the original model still impresses

The Mission 770 story starts with the BBC. The broadcast corporation's famed engineering department did a great deal of research into speaker design during the 1960s. Spencer Hughes was one of the engineers working on the research projects, and he went on to found Spendor. Using the knowledge gained during his time with the Beeb, Hughes designed Spendor's first product, the BC-1 loudspeaker, in 1969. This was a hugely influential design and set the template for what many still think of as the BBC (or British) sound.

Let's fast forward a few years. It is now 1977 and Farad Azima founds Mission. He, like many, admires the BC-1, but he also thinks it can be bettered. Azima points to weaknesses in the bass and the restrained presentation. The fruit of his labour arrives a year later - the 770. These speakers are priced at £357 in the UK and are therefore direct competitors for the Spendors.

At just short of 60cm tall and with an internal volume of 40 litres, the two-way 770 speakers are just a touch smaller than their rivals. Mission follows the BBC principles of having a thin-walled cabinet construction (using chipboard) damped by heavy bitumen. The thinking is that, no matter how rigid, all cabinets resonate to some degree. If you allow the panels to flex a little and apply strong damping, you end up with a well-controlled box that moves unwanted vibrations away from the all-important midrange frequencies and into the bass, where our ears are less sensitive.

Cutting-edge technology

The 770's 21cm mid/bass unit uses a polypropylene cone. This was considered cutting-edge technology at the time and was tuned with a front-firing port. Higher frequencies, above around 3kHz, were taken care of by a modified SEAS 25mm soft-dome tweeter. The two drivers were linked by an unusual crossover network that had gentle slopes and was designed with phase behaviour in mind.