JAMO D 4 - Manual (Page 6)

6
D 4CEN
D 4CEN is a 2 way bass reflex system featuring two 4½”
woofers and a 1” DCD tweeter.
The design of D 4CEN is kept as compact as possible in
order to make it easier to place the speaker close to the
TV set. So, the height of just 16-cm/6.3 inch is just
enough to house the two powerful 4½” drivers.
Actually, you would probably expect that in order to
obtain optimum timbre matching between centre and
front speaker you need to use the same size of driver.
What happens when placing too much cone area in a
relatively compact cabinet is an overshoot before the
woofers starts to roll off. This overshoot is often heard
on centre channel speakers as if the sound was
recorded with the microphone placed directly on the chest of the actor – not exactly
contributing to voice intelligibility!
The cone area of the two 4½” woofers equals less than that of one 6½” woofer, but due to
the fact that the two woofers are placed closely together and that they are working in the
same frequency range they load each other at the lower midrange frequencies. This means
that in this range the cone area equals a 6½” woofer. So, actually by reducing the cone area
we achieved exactly what we wanted; acoustically identical drivers and thus a seamless
transition between the front speakers.
The D 4CEN is of course magnetically shielded, for placing in the vicinity of a normal CRT
type TV.
D 4SUB
The D 4SUB is equipped with two very powerful 8”
woofers in a closed cabinet.
The advantage of using two 8“ woofers instead of one
large is higher power handling capability - as the heat
is disposed of in two voice coils/magnet systems - and
a more compact design – making it a lot easier to find
a suitable placing of the subwoofer.
The cone area of the two 8” woofers equals the size of
an 11” woofer.
The class D amplifier delivers solid 400 watt
(continuous output) – more than enough to secure
sufficient headroom – even for a subwoofer reaching down to 22Hz (- 6 dB).
The stand by power consumption is <1 watt – so unless you are not using the subwoofer
for a longer period of time, there is no need to disconnect it from the mains. Just let the
automatic on/off circuitry do the daily job for you.
Thanks to the heavy MDF board cabinet, the powerful amplifier, and the specially
developed woofers, the D 4SUB delivers a deep, precise and detailed reproduction of the
low register - perfectly matching the sound from the D 4 front speakers.