KEF Audio 3000 Series Subwoofer Technology, Specifications, Subwoofer Drive Unit, Electronics

Subwoofer Technology Specifications

Subwoofer Drive Unit

Heavy weight long-throw motor design with aluminium Faraday ring for reduced distortion.

Magnetically shielded.

4-layer copper coil for high power capacity. FEA1 optimised coil and magnet design to give a linear BL profile2.

Rear suspension and surround FEA optimised to give maximum linear excursion resulting in reduced distortion.

Electronics

Highly efficient 250W class D amplifier.

Thermal and overcurrent protection built into the amp and power supply unit ensuring ultra reliable performance.

Auxiliary Bass Radiator (ABR)

Balanced symmetrical low profile ABR design for more linear excursion and reduced distortion.

Internally	vented ABR air cavity resulting
in less	compliance damping giving better

LF performance.

Sophisticated limiter system to prevent voltage overload is optimised for maximum

audio quality3.

Model	HTS3001	HTC3001	HTB2
Design	Bass reflex two-way	Closed box three-way	Powered Subwoofer
			Passive radiator
Drive Unit Array	115mm (4.5in.) Uni-Q	115mm (4.5in.) Uni-Q	1 x 250mm (10in.)
	19mm (0.75in.) aluminium HF	19mm (0.75in.) aluminium HF	+ 1 x 250mm (10in.) ABR
		2 x 75mm (3in.) LF
Frequency Range	70Hz - 55kHz	65Hz - 55kHz	30Hz - 250Hz
Amplifier Requirement	10 - 100 Watts	10 - 100 Watts	250 Watts built in
Sensitivity (2.83V/1m)	88dB	90dB	n/a
Maximum Output	108dB SPL @ 1m	110dB SPL @ 1m	110dB SPL @ 1m
Impedance	8Ω	8Ω	n/a
Internal Volume	1.75 litres	2.4 litres	15 litres
Weight	2kg (4.5lbs)	2.6kg (5.8lbs)	11.3kg (24.9lbs)
Dimensions (H x W x D)	245 x 125 x 150 mm	130 x 300 x 185 mm	vertical:
	9.6 x 4.9 x 5.9 in.	5.1 x 11.8 x 7.3 in.	390 x 440 x 195 mm
			15.4 x 17.3 x 7.7 in.
			horizontal:
			227 x 440 x 385 mm
			8.9 x 17.3 x 15.2 in.
Finish	High Gloss Black or	High Gloss Black or	High Gloss Black or
	High Gloss Silver	High Gloss Silver	High Gloss Silver
Dispersion	Over 90º arc with 2dB	Over 90º arc with 2dB
	reference, both horizontal	reference, both horizontal
	and vertical	and vertical
Harmonic Distortion	2nd and 3rd harmonics	2nd and 3rd harmonics
	(90dB, 1m)	(90dB, 1m)
	<0.8% 120Hz - 30kHz	<0.8% 120Hz - 30kHz
	<0.3% 250Hz - 22kHz	<0.3% 250Hz - 22kHz
Crossover Frequency	2.2kHz	500Hz / 2.2kHz
Power Requirements			100 - 240V ac 50 - 60Hz

Items are available separately, or packaged as a complete system.

1FEA = Finite Element Analysis - a design development process where individual components are modelled and analysed within a computer program.

2BL profile = measurement of the motor force factor on the speaker driver over the working displacement of the magnetic coil.

3Opto-coupled LED and light sensitive resistor senses overdrive and automatically limits this to prevent damage to the unit.

GP Acoustics (UK) Ltd. reserve the right, in line with continuous research and development, to amend or change specifications without prior notice. E. & O.E.