The BBC LS5/8

The LS5/8 is the BBC’s flagship design, and was developed because of the
need for higher sound pressure levels and greater transparency and
consistency than the ageing LS5/5 offered. This was the first BBC
loudspeaker to use a polypropylene diaphragm which, being lighter
than Bextrene, offered greater efficiency and lower colouration. A
carefully researched cone profile enables the unit to work successfully
well into the midrange.

After many months of intensive development, the Graham Audio LS5/8
refines the concept further. Designed in conjunction with Derek Hughes
and Volt Loudspeakers and manufactured under license in the UK, it
features a unique 12 inch bass/mid unit that is married to the same 34mm
Audax tweeter that is used in the LS5/9.

As with all our BBC monitors, the cabinet is a finely tuned structure
that uses high quality birch plywood and hardwood batons. The 12mm panels
are mass-loaded to move resonances away from the midrange region and
Rockwool is used in preference to cheap foam for air damping.

The design retains the same midrange clarity and balance of the LS5/9,
but offers an extended bass response and greater authority at high level
in larger rooms. The continuity of sound quality between the two designs
means that engineers can move between the two different loudspeakers with
complete confidence during the recording and mastering process.

The LS5/8 was originally conceived as an active design, but Derek Hughes
has designed a passive crossover that greatly improves on the resolution
and imaging of the original design while still conforming to the demanding
BBC specification.