A floorstanding three-way centre speaker with powered bass: an XStat CLS electrostatic panel 87.6 cm wide, two Folded Motion XT tweeters and four 16.5 cm woofers driven by a 250 W Class D stage, with ARC readiness.
Illusion ESL C34A: how it is built
The Illusion ESL C34A is the reference centre channel of the Masterpiece series, voiced to match the floorstanders of that family and complete a multichannel system. It does not hang on a wall: this is a floor-standing cabinet 82.2 cm wide and 60.3 cm high, weighing 40.9 kg. The curved 20.3 x 87.6 cm panel, with 1,778 cm² of radiating area, covers the midrange between 500 Hz and 2,000 Hz. Stated response is 45-23,000 Hz within ±3 dB, with 90 dB sensitivity and 6 ohms impedance.
Treble is entrusted to two Folded Motion XT units whose pleated diaphragms measure 11.4 x 7 cm apiece, hidden directly behind the electrostatic panel: a position that avoids diffraction and improves phase coherence between mids and highs. The accordion-like diaphragm squeezes air between its folds and, according to MartinLogan, needs nearly 90% less travel than an ordinary 25 mm dome, with much lower distortion. That leaves the panel free to concentrate on the midrange, meaning voices and dialogue.
Lower down, four 16.5 cm aluminium woofers receive 250 W from a Class D stage, supervised by a 24-bit Vojtko processor. The section is prepared for Anthem Room Correction, which with the optional measurement kit fits the bass to the room; manual bass and mid-bass adjustments remain available all the same. The extruded-aluminium AirFrame Blade frame ties the panel to the cabinet and the terminals are pure-copper WBT. The suggested external amplifier runs from 20 to 600 W. The speaker is offered in several finishes.
Specifications
- Frequency range: 45-23,000 Hz (±3 dB)
- Sensitivity: 90 dB (2.83 V at 1 m)
- Impedance: 6 ohms
- Suggested amplifier: 20 to 600 W a channel
- Crossover points: 500 and 2,000 Hz
- Horizontal spread: 30°
- Tweeters: two Folded Motion XT, 3.2 x 6.1 cm, each with an 11.4 x 7 cm diaphragm
- Midrange: XStat CLS electrostatic panel, 20.3 x 87.6 cm, radiating area 1,778 cm²
- Woofers: four 16.5 cm aluminium units on cast baskets
- Bass amplification: Class D stage of 250 W into 4 ohms (500 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): 60.3 x 82.2 x 58.6 cm
- Weight: 40.9 kg
- Supplied: sold singly
- Finishes: gloss black, gloss white, cherry, walnut, silver, burgundy, dark blue, Desert Silver, grey, red, basalt black
