A large hybrid electrostatic floorstander, supplied as a pair: an XStat CLS panel 38 cm wide and two 30.5 cm woofers with 500 W of Class D power each, governed by a 24-bit DSP and prepared for ARC room correction.
Renaissance ESL 15A: panel, woofers and electronics
The Renaissance ESL 15A is the largest Masterpiece model with a powered bass section. Its curved panel reaches 117 x 38 cm, equal to 4,446 cm² of radiating area, and behaves as a line source almost 117 cm tall; at 300 Hz it hands over to two 30.5 cm woofers with aluminium cones. Stated response extends from 22 Hz to 21,000 Hz within ±3 dB, sensitivity is 92 dB and the suggested external amplifier ranges from 20 to 700 W per channel.
Each woofer has its own 500 W Class D stage, with 1,000 W available on peaks, and its own closed volume. Ahead of the power stages a 24-bit Vojtko processor sets the low-pass filter, the equalisation and the woofer protection entirely as digital maths. The two drivers are placed one at the front and one at the back and fed with different phase following the PoweredForce Forward scheme, which cancels much of the bass heading for the rear wall and gives a more even response in the room.
For positioning MartinLogan quotes at least 30 cm between the back of the cabinet and the wall and about 75 cm for the panel, which as a dipole needs free air to its rear. ARC correction, enabled with the measurement kit bought separately, measures the bass in the room and brings it back to the reference curve. The crossover for the electrostatic section uses polypropylene capacitors, air-core coils and a toroidal transformer; the WBT terminals have a pure-copper conductor. The rear plate also holds the bass adjustments and the LED light dimmer.
Specifications
- Frequency range: 22-21,000 Hz (±3 dB)
- Sensitivity: 92 dB (2.83 V at 1 m)
- Impedance: 4 ohms nominal, 0.5 ohms at 20 kHz
- Suggested amplifier: 20 to 700 W a channel
- Crossover point: 300 Hz
- Horizontal spread: 30°
- Electrostatic panel: XStat CLS, 117 x 38 cm, radiating area 4,446 cm²
- Woofers: two 30.5 cm PoweredForce Forward aluminium units on cast baskets
- Bass amplification: two Class D stages of 500 W into 4 ohms (1,000 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
- Lighting: LED with three levels, full, dimmed, off
- Terminals: WBT-0703Cu nextgen in gold-plated pure copper
- Other sockets: mains, RJ45 and mini USB for ARC
- Size (H x W): 177.3 x 40 cm
- Weight: 63.5 kg each
- Supplied: sold as a pair
- Finishes: gloss black, basalt black, gloss white, cherry, walnut, silver, burgundy, dark blue, Desert Silver, grey, red
