QUAD ESL 2905, ESL 2805 manual Principle

electrostaticThe

principle

1.

Naturally produced sound emanates from a point. Virtually no loudspeaker comes close to achieving this – but the Quad approach comes closest of all.

The ESL is dipolar, producing front and rear radiation. It has no box so there is no colouration. Using large panels ensures well-maintained bass to well below 40Hz. The centre two panels in each Quad ESL Loudspeaker incorporate concentric rings on the outer grid-plates around the diaphragm. Each ring is subjected to a minuscule time delay and attenuated by its own individual circuit, the sound spreading gradually from the centre outwards through each successive ring. This carefully structured delay line creates

anear-perfect spherical wave front originating from an apparent point 400mm behind the loudspeaker. Imaging is pinpoint and there is no ‘sweet spot’ – all listeners receive a full sonic presentation.

The result is a loudspeaker of unsurpassed accuracy. The Quad ESL is probably the lowest distortion loudspeaker ever made.

1.A perfect point source produces a spherical wave pattern.

2.The air particle movement at a plane some distance from the source.

An identical movement in the ESL

3.membrane produces and identical wave front

The membrane carries a constant

4.charge. The charge on the electrodes fluctuates according to the music signal.

5.The music signal is fed first to the centre section, then to each ring in turn via delay coils

2.

3.

4.
	High Resistivity
Electrodes	Membrane
	Polarising
	Voltage
Input	Input
Transformer

5.

8