Quad ESL-988, ESL-989 Brochure

Quad has long been regarded as one of the finest hi-fi companies in the

world. A reputation based on product innovation, and quality in design

and manufacture.

The finest of these product lines has always been our ESL range of

speakers. The speed, neutrality, lack of colouration and continuity of

frequency response has remained unparalleled since the very first

ESLs. Today, they are one of, if not

the

, most advanced loudspeakers

in existence – and the only ones capable of tracking a square wave

perfectly. Working at up to 5000 Volts, with an almost mass-less

diaphragm – and with no crossover, they avoid most of the problems

that have plagued cone loudspeakers over the last century.

The ESLs produce an incredibly detailed, coherent soundstage

capable of breathtaking performance that will thrill listeners for many

years to come.

THE QUAD ESL

For the closest approach to the original sound...

‘Even if price weren’t an issue I’d be hard pushed
to find speakers that better the 988s’ combination
of talents...I can’t recommend them too highly’

Gramophone (March 2001)

The Quad ESL is fundamentally different from

conventional loudspeakers and even other

electrostatic designs. Whilst most conventional

speakers use cone type drive units and a coil moving

in a magnetic field, Quad uses the full-range

electrostatic principle. The sound is not created by a

cone but by a microscopically thin diaphragm, less

than one tenth the thickness of a human hair. This

ultra-low mass diaphragm is coated with a conductive

material and is stretched between two fixed electrode

plates. The electrodes both carry a high positive

charge and the diaphragm carries a negative charge.

The size of the charge on each of the electrodes rises

and falls to track the waveform of the musical signal;

so attracting and repelling the diaphragm closer to

and further from one or the other electrode plates. It

is the movement of the almost mass-less diaphragm

that creates the sound we hear.

Quad's unique ESL system takes the performance of

electrostatic loudspeakers a step further. Acousticians

have long recognised that the ideal loudspeaker

should be a point source from which the waves of

sound radiate in a fashion rather like the ripples

resulting from a pebble dropped into a lake. It is

obvious that large cones and even larger

electrostatic diaphragms cannot be point sources, so

how can they be made to behave more like the perfect

loudspeaker?

Quad have solved the problem with an elegant

engineering solution that has subsequently been

awarded a patent. Instead of a large single electrode,

Quad designed a number of electrodes arranged as a

series of concentric rings. Each electrode is fed with

a calibrated delay line so the sound first leaves the

centre of the speaker then, after a short delay, the

sound leaves the next ring and so on. The delayed

sounds build up into a spherical waveform identical to

that produced by a theoretical point source. This

innovative step has brought closer the achievement of

the perfect loudspeaker.

The Quad ESL is a premiére music reproduction

loudspeaker constructed from the finest materials

with meticulous attention to detail. It reaches the

pinnacle of high-fidelity performance with an

unparalleled ability to sonically 'disappear', and

create convincing three-dimensional sound stages.

Instruments and vocals occupy precise, accurately

sized locations in space, giving an uncanny realism to

reproduced sound.

‘When I return the 988s it will be in a package
much too small for the speakers, but just large
enough to carry a check for their remittance.’

The Absolute Sound (July 2001)

‘Going back to conventional

speakers afterwards merely

highlights how great the 989 is’

Hi-Fi News (July 2000)

‘The Best Late Night Speakers in

The World...ever!’

Hi-Fi World (December 2000)

And a choice of size and finishes...

‘Quad has done it again: the 988s are
world class - the single driver
presents a fabulously together sound
that’s tough to match at any price’

What Hi-Fi? (December 2000)

For the first time ever, the ESLs are available in choice of size and

finish. The ESL-988 is a replacement for the much-loved ESL-63 and

with it, brings a new level of detail and cleanliness around the

mid-band. Much lighter and stronger MYLAR is used, the signal path

has been cleaned, higher specification components, especially the

transformers have been used throughout – but above all, the structural

rigidity has been improved beyond all recognition, the result being to

improve dynamics and extend the frequency response lower.

The ESL-989 features additional panels to further extend the frequency

response and negate the need for any kind of sub-woofer, even with

the deepest and most dynamic recordings. This is Quad’s flagship

product and is undoubtedly one of the finest transducers in the world.

The new ‘vintage’ and ‘nouveau’ finishes have been added as an

alternative to the original black finish, for easy integration into a wide

variety of home furnishings.

Maximum Power Output

Sensitivity

Impedance

Max. Cont. Input Voltage

Programme Peak

Permitted Peak

Axis band limits

AC Double Insulated Input

Dimensions mm (H x W x D)

Weight

2N/m2@ 2m

86dB/2.83V RMS

8 ohm nominal

10V RMS

40V

55V

-6dB @ 35Hz

-6dB >20kHz

110–120V
or 220–240V

1335 x 670 x 315

25.3kg net

2N/m2@ 2m

86dB/2.83V

RMS

8 ohm nominal

10V

RMS

40V

55V

-6dB @ 35Hz

-6dB >20kHz

110–120V
or 220–240V

940 x 670 x 315

20.5kg net

Model

ESL 989

Specifications

Finishes

ESL 988

Nouveau

Vintage

Black

IAG House

Sovereign Court

Ermine Business Park

Huntingdon. PE29 6XU

Tel : [phone]

Fax : [phone]

Email: [e-mail]

www.quad-hifi.co.uk