Whitepaper

The large diameter driver ensures linear operation
with minimum compression. This, together with the well
controlled breakups of the paper fibre cone diaphragm,
means that even the most minute music details, stands out
crystal clear.
It also means that the sound never gets tiring, even aer
hours of listening.
Leak control
The bass performance of a headphone is incredibly
sensitive to leaks between the headphone and the head.
Variations in leakage can result in low frequency variations
of up to 20dB.
On the DALI IO headphones we have designed the ear pads
specifically to achieve minimum leak variation, ensuring that
every user will experience the sound as we intended.
Cavi design
Being a closed back headphone, the driver is mounted in an
enclosure like a miniature loudspeaker cabinet.
With loudspeakers, the main purpose of the cabinet is to
isolate the front and rear surfaces of the diaphragm from
one another, in order to create low frequency output. The
speaker cabinet simply prevents the air pressure on the
front of the diaphragm from being cancelled by the reverse
phase air pressure rear of the diaphragm.
With headphones on the other hand, the front and rear
side of the diaphragms are isolated by the ear pad, so there
is no need for the driver to sit in a sealed enclosure to
create bass.
However, if there is no enclosure behind the headphone
driver, the only barrier between the ear and the ambient
noise will be the thin diaphragm of the driver, and that oers
very minimal acoustic isolation. The driver plays as loud
on the rear surface as on the front, so with no enclosure
the music heard by the headphone user will be equally as
audible to everyone.
Although the main purpose of the enclosure is dierent for
headphones compared to loudspeakers, the principles and
requirements for good enclosure design are the same.
As with loudspeaker cabinets, the headphone enclosure
needs to be as rigid and well damped as possible, because
even low levels of enclosure vibration will colour the
headphone sound. On the DALI IO headphones, the
enclosure design has been optimised and strengthened
for minimum resonances. The enclosure material has been
specially selected to minimise the enclosure vibration.
Additionally, to improve the passive noise isolation
performance, a special vibration damper is incorporated
between the driver and rear wall of the enclosure.
DALI SOUND
DALI A/S www.dali-speakers.comDALI IO 9