SPH-135TC
1 x Single Unit - 5 1/4" Bass/Mid KEF
B110 upgrade JR149 JR150 LS3/5a 4/8/16 Ohms 60w
A versatile
high power 5 ¼ " loudspeaker that is an excellent replacement for
the renowned KEF B110 driver and the French Audax equivalent, which
were used in the BBC LS3\5A and the Rogers JR149 / JR150's.
This
loudspeaker has dual 8 ohm voice coils so that it can be wired as
a 4, 8 or 16 ohm driver making it ideal for some 4 and 16 ohm derivatives
of other designs.
This
gem of a loudspeaker is particularity suitable for modern high performance
closed (sealed) LS3\5A type of speaker projects. The choice of impedance
also makes this an excellent candidate for the twin Di-Apolito (MTM)
midwoofer - tweeter - midwoofer arrangement, so that a final impedance
of 8 ohms can be achieved. Detailed impedance wiring instructions
are included with the driver.
This
speaker is somewhat superior in design to the KEF B110 driver in
so much that it is able to take advantage of modern materials, far
superior test methods and quality control systems. I was an development
engineer at Marconi's during the 60s - 70s and I know how basic
and primitive the test equipment was back then. No CAD systems and
a basic calculator without a % key cost over a £100.00
The
KEF B110 had a Bextrene cone (Rubberised polystyrene coated with
Platiflex) later called Acoustilene, wow. Despite these flashy names
the B110 suffered from some really nasty cone resonance's which
are not apparent in this modern replacement which has a light weight
Polypropylene cone and despite another flashy name this works well
and produces a nice smooth damped response without awful resonance's.
Modern
materials used in the voice coil assembly plus a vented pole piece
have increased the RMS power rating from the B110's 15 watts to
this loudspeakers 60 watts.
I have
included the full loudspeaker specification below so please feel
free to scroll down the page to see Frequency Plots, Dimensional
Information, Photo's of the loudspeaker and the driver fitted into
my JR149 in place of the B110 The loud speaker will rear mount behind
a 4 ¾ " hole like the LS3\5A, the rear of the speaker has a stepped
chassis which will fit into a ?? hole. I supply a gasket with each
loudspeaker so that it effectively removes the step and is then
similar to the B110 for fitting into a ?? hole
If
you wish to make your own bespoke cabinets this little driver is
ideal. It can be used in sealed designs From 6 litres to 15 litres
and ported up to 20 litres. A couple of examples that I ran though
my software produced these results -
Sealed
8.5 litre cabinet, Q 0.7, -3dB @ 71Hz
Ported
16.25 litre cabinet, Port 4.7Cm dia x 16.2 Cm long, -3dB @ 36.5Hz
This
should give you some idea of box size, the above results are straight
out of a simulator software and do not assume the use of wadding.
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