ESL 2912X Electrostatic Speakers
ESL 2912X Electrostatic Speakers
Demo the sublime ESL 2912X in store at Yorkshire AV from mid-August.
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.
The ESL 2912X is the flagship QUAD electrostatic loudspeaker. Featuring an expanded six-panel design for increased radiating area, higher sound pressure levels, dynamics and extension, the ESL 2912X delivers an immersive listening experience with deeper bass and rich textures, bringing even the most complex music to life. Built for the ultimate audiophile experience, it offers enhanced dynamic range, improved headroom, and a spacious soundstage.
The Beginning
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.
This approach encompassed a thorough analysis of every process, step, technique, material, tool, and jig employed in the construction of a QUAD ESL, with the aim of improving the quality and precision of the electrostatic loudspeaker assembly.
Leveraging techniques such as advanced laser-precision metrology, QUAD undertook an exhaustive review of the foundation of the ESL design. Systematic enhancements were implemented in the processes of spraying, etching, tensioning, and assembly to ensure peak performance. Rigorous upgrades were applied to implement both passive and active components, enhancing the overall system integrity of the then-current ESL 2912 and 2812 models.
The team of QUAD engineers considered the results of this lengthy and time-consuming self-appointed audit so significant that they deemed it worthy of a new model in the lineage of the ESL programme.
It is widely accepted that enhancing an ESL is fundamentally an exercise in building upon existing frameworks through incremental improvements rather than pursuing radical innovations. Consequently, QUAD did not require a complete overhaul of established methods. Nonetheless, these incremental advancements have now culminated in a significant transformation of the 2912 and 2812 models into what is now known as ESL X.
The History
In 1957, QUAD founder Peter Walker shattered conventions with the introduction of the first full-range electrostatic loudspeaker, achieving transient response and clarity then considered impossible.
Subsequent models (ESL-63, ESL988/989, ESL 2805/2905, ESL 2812/2912) each introduced incremental refinements. Critics have long hailed these models for their airy, effortless midrange and natural box-less hear-through qualities.
High Voltage & Low Distortion
One critical factor influencing the ESL’s performance is its notably high operating voltage – approximately 5,250 volts. This elevated voltage substantially enhances the diaphragm's control and linearity, allowing it to move with precision in response to musical signals while significantly reducing distortion.
A QUAD ESL rigorously regulates this high voltage via a multiplier circuit that amplifies standard AC power, complemented by a protective circuit designed to prevent overdriving (excessive input power), thereby safeguarding the speaker from potential damage and distortion.
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.
Major upgrades
The first technical improvement sees the operational PCB split from a monolithic design into three fully independent modules. The system comprises a High-Voltage Multiplier Module, a Control and Protection Module, and a Low-Voltage Signal Module. Together, these components form an integrated unit designed for optimal performance and reliability. By physically segregating the 5.25 kV multiplier stage from the sensitive low-voltage circuits, QUAD significantly diminish stray high-voltage electric fields. This isolation strategy not only minimises interference and crosstalk but also markedly enhances stability and noise performance. The resulting effect is crystal-clear audio signals that faithfully reveal every nuance, even during powerful musical peaks.
Peter Comeau, QUAD’s Director of Acoustic Design, has monitored the development of the ESL X closely and comments as follows:
Peter Comeau, QUAD’s Director of Acoustic Design, has monitored the development of the ESL X closely and comments as follows:
“The X suffix for the new QUAD ESL 2912 and 2812 speakers suggests something eXtra and that is certainly delivered in the sonic performance of these models.
First of all the inclusion of UK built audio transformers, built precisely to Peter Walker’s original specification, provides wider bandwidth, especially at the high frequency end where the extra extension offers superior clarity to instrumental harmonics as well as lending more air to the spatial acoustics.
Secondly, an all new PCB board layout splits the audio components from the high tension section and optimises the latter to provide a more stable 5kV supply to the electrostatic panels. This benefits both the precision of instrumental timbres and, not surprisingly, the transient attack, particularly in the bass region. Finally a new grille cloth, specially chosen to match the matt black finish of the speakers, offers improved acoustic transparency which helps realize the full benefits of the new internal components.
The result is yet another incremental advance of the musical performance of the QUAD ESL, still considered the most uncolored, natural and transparent-to-the-source hi-fi loudspeaker.”
Specifications
| Model | ESL 2912X |
| Format | loor 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 | 6 |
| 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 - 20 Ohms |
| Maximum Input | Continuous input voltage (rms): 10V Programme Peak for undistorted output: 40V Permitted peak input: 55V |
| Frequency Response | 32Hz - 21kHz (-6dB) 28Hz - 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) | 1470 x 690 x 380 (mm) |
| Net Weight | 44kg |