A hybrid electrostatic floorstander, supplied as a pair, with an XStat CLS panel 28 cm wide and powered bass: two 20.3 cm woofers driven by two 275 W Class D stages and prepared for ARC room correction.
Impression ESL 11A: the design
Within the Masterpiece series the Impression ESL 11A is the most compact of the models with a powered bass section. Its curved panel measures 112 x 28 cm, giving 3,136 cm² of radiating surface, and covers the range above 300 Hz; lower down, two 20.3 cm aluminium woofers do the work, each with its own power stage. Stated response is 29-23,000 Hz within ±3 dB and sensitivity is 91 dB; for the external amplifier MartinLogan quotes 20 to 550 W per channel.
The two woofers sit in separate sealed chambers, one facing the listener and one facing the rear. PoweredForce Forward technology manages their relative phase to tame the energy that would otherwise bounce off the wall at the back of the loudspeaker: that is why the cabinet can stand fairly near the wall, at a distance at least equal to the woofer diameter, about 20 cm, whereas the panel wants roughly 75 cm. Low-pass filtering, equalisation and limiting for the woofers are handled by a 24-bit Vojtko digital processor.
The bass section is ready for Anthem Room Correction: with the measurement kit, which is bought separately, the system reads the low-frequency response in the room and corrects it. On the back are the dedicated RJ45 and mini USB sockets, a bass adjustment below 75 Hz (±10 dB) and a three-position switch for the mid-bass. The signal enters through pure-copper WBT terminals. The extruded-aluminium AirFrame Blade frame joins panel and cabinet without masking any of the active surface.
Specifications
- Frequency range: 29-23,000 Hz (±3 dB)
- Sensitivity: 91 dB (2.83 V at 1 m)
- Impedance: 4 ohms nominal, 0.6 ohms at 20 kHz
- Suggested amplifier: 20 to 550 W a channel
- Crossover point: 300 Hz
- Horizontal spread: 30°
- Electrostatic panel: XStat CLS, 112 x 28 cm, radiating area 3,136 cm²
- Woofers: two 20.3 cm aluminium units on cast baskets, in separate sealed chambers
- Bass amplification: two Class D stages of 275 W into 4 ohms (550 W peak)
- Processing: 24-bit DSP preamplifier for the woofer section
- Room correction: ARC ready, measurement kit bought separately
- Adjustments: bass ±10 dB below 75 Hz, mid-bass -2/0/+2 dB, ARC engaged or bypassed
- Terminals: WBT-0703Cu nextgen in gold-plated pure copper
- Other sockets: mains, RJ45 and mini USB for ARC
- Size (H x W x D): 154.3 x 30.2 x 69.6 cm
- Weight: 40.9 kg each
- Supplied: sold as a pair
- Finishes: gloss black, basalt black, gloss white, cherry, walnut, silver, dark blue, burgundy, Desert Silver, grey, red
