Quad ESL 2812X Electrostatic Speakers
Quad ESL 2812X Electrostatic Speakers
The ESL X concept began in 2019 as part of an intensive review of the QUAD Electrostatic manufacturing facility—a suite dedicated solely to the production of QUAD ESL loudspeakers.
In a unique four-panel design but sharing the same treble and midrange panels as the flagship ESL 2912X, the more compact 2812X model delivers the signature QUAD sound—ultra‑transparent, highly detailed and effortlessly natural, with a midrange so lifelike that vocals and acoustic instruments appear in the room. Yet, all of this is provided in a smaller, lighter and less imposing format - at just 1070mm high.
The ESL-X concept began in 2019 as part of an intensive review of the QUAD Electrostatic manufacturing facility—a suite dedicated solely to the production of QUAD ESL loudspeakers. Under the expert leadership of Paul McConville, (a gentleman recognised as the world’s foremost authority in QUAD ESL engineering, with 40 years of experience), every aspect of the original design underwent a comprehensive evaluation and meticulous refinement.
The Heart
One would be rightly forgiven for knowing of the ESL but not knowing how the ESL differs from typical loudspeakers. It us correct to begin with the fact that a QUAD ESL is not your typical loudspeaker! Unlike conventional speakers that use moving-coil drivers, the ESL employs a completely different principle: an electrostatic panel.
At the heart of a QUAD ESL are panels containing a diaphragm of fine Mylar film, ten times thinner than a human hair. The Mylar film is coated with a high resistance conductive material and suspended between two perforated metal plates called stators.
This unique diaphragm is incredibly light and therefore dynamically responsive. It is much lighter than any moving-coil driver cone and can therefore respond to signal transients with incredible speed and accuracy.
The Mylar diaphragm is charged up to a constant high voltage exceeding 5.2kV DC. An audio signal is applied across to the two stators to create an alternating electric field, which causes the charged electrostatic Mylar diaphragm to be alternativley pushed and pulled towards them. As a result, the diaphragm vibrates accurately in response to the music signal, and so produces the ultra-pure sound reproduction for which QUAD ESL loudspeakers are well-known.
Due to the diaphragm's lightweight nature and uniform drive across its entire surface, the sound it generates is exceptionally clean, responding accurately to musical transients, and exceptionally low in distortion, particularly intermodulation distortion. This is particularly evident in the midrange frequencies, where human hearing is most attuned.
The Improvements
The intricate details of the manufacturing process contribute significantly to the refinements that are more than audible in the ESL X. For one, the time taken to manufacture a single QUAD ESL panel is extended, therefore the time frame for a full ESL loudspeaker system to be assembled is much more considered. The process is one of extreme care and attention to detail.
However, dig even deeper and QUAD engineers have taken things to the ‘X level’ with some intriguing further enhancements.
Specifications
| Model | ESL 2812X |
| Format | Floor standing dipole with 3° fixed tilt |
| Type | Multiple electrostatic drive membranes |
| Point Source Time Delay | Progressive concentric rings |
| Chassis Structure | Heavy duty composite aluminium / steel |
| Panel Elements | 4 |
| Maximum Output | 2 N / m2 at 2m on axis |
| Sensitivity | 1.5 mbar per volt referred to 1m (86dB/2.83V rms equivalent) |
| Nominal Impedance | 8 Ohms |
| Impedance Variation | 4 - 15 Ohms |
| Maximum Input | Continuous input voltage (rms): 10V Programme Peak for undistorted output: 40V Permitted peak input: 55 |
| Frequency Response | 37Hz - 21kHz (-6dB) 33Hz - 23kHz (useable) |
| Directivity Index | See Polar Diagrams |
| Distortion (100dB @ 1m) | Above 1000Hz <0.15% Above 100Hz <0.5% Above 50Hz <1.0% |
| AC Input | 220 - 240V, 100-120V |
| Power Fuse | 100mA anti-surge, 200 - 240V 200mA anti-surge, 100 - 120V |
| Power Consumption | 8W |
| Dimensions (H x W x D) | 1070 x 690 x 380 (mm) |
| Net Weight | 35kg |