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Lorenz S-888

Pair of Lorenz S-888 8 inch Fullrange Drivers

ITT (International Telephone and Telegraph) Lorenz S-888 is a fine vintage full-range driver from fifties. It can be easily recognized by the bright red color of its whizzer cone which is due to the substance with which it has been soaked for more rigidness. The paper surround is a common part of the membrane and it is lubricated. In the example I own the lubricant is still soft and a little bit sticky. The driver has a lightweight aluminum alloy chassis and aluminum magnet protecting cap.

This is the manufacturer's brochure published in High Fidelity Magazine 1959 Link To Lorenz S-888 Manufacturer's Datasheet


My Measurements

Driver Properties Thiele - Small Parameters
Chassis material Die-cast aluminum alloy   Parameter Measured Datasheet
Membrane material Paper Fs 64.6Hz N/A
Magnet System Ferrite Re 5.9 Ω N/A
Surround Impregnated Paper Qms 5.1 N/A
Voice Coil Diameter 28 mm Qes 0.72 N/A
Nominal Impedance 8 Ω Qts 0.63 N/A
Sensitivity 89 dB/W/m   Vas 16 ltr N/A
Rated Power 18W Le 0.24 mH N/A

SPL Responce of Lorernz S-888 at 1m on axis and 15 30 deg off axis 

Frequency response at 1m with 2.83 V input RED - on axis, BLUE - 15 º off axis, GREEN - 30 º off axis
This driver delivers an excellent off-axis performance without any remarkable peaks and dips even at 30 º.

Lorenz S-888 second, Third and Fourth Harmonic in 18 ltr sealed box 

The second, third and fourth harmonic curves measured at 2.83V input RMS.

Lorenz S-888 Burst decay Responce at 1m in the Universal Horn

Burst decay response, measured at 1m on axis

Lorenz S-888 impedance in 18 ltr seled box 

The impedance curve in 18 ltr sealed box


ITT S-888 can be used in sealed vents as well as in open-baffle constructions. A good idea is to try it in a TL, but I've never tried it. Midrange is not boosted, as we can expect from the SPL curves, the sound is smooth and un-fatiguing without any coloration in the middles. The upper range is a bit faded, but when it is combined with a proper amplifier (SE with EL-34 is a good example), for my taste it still don't need support with a tweeter.

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