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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