Nine

About the Nine

The KLH Nine is a pioneering full-range electrostatic speaker originally designed by Arthur A. Janszen and produced by KLH starting in the late 1950s. It features two large, flat panels approximately 70 inches tall, 23.5 inches wide, and under 3 inches deep, framed in finely finished wood with a boucle fabric grille and a perforated metal rear screen protecting the electrostatic elements. Each panel contains a two-way electrostatic system with a small tweeter panel handling frequencies above 2kHz and eight large woofer strips covering the lower range. The speaker operates as a dipole, radiating sound from both front and back, providing a combined radiating area of about 28 square feet. It requires dedicated outboard power supplies that provide 6kV polarizing voltage and draws about 5W at 115V AC. The system delivers a smooth frequency response from about 40Hz to beyond 20kHz, with a slight high-end rise that adds an open, airy quality without harshness. The Nine is known for its superb transient response, low distortion, and a soundstage that can recreate concert hall realism. It is highly sensitive to amplifier quality and input signal cleanliness, recommended to be driven by at least 30 watts per channel but no more than 100 watts RMS, with a nominal impedance of 16 ohms. The speaker was produced in limited quantities (around 5,000 pairs) and is considered one of the most significant loudspeakers historically. Modern reissues and restorations maintain the original design ethos, with finishes available in mahogany, walnut, and oiled walnut. The speaker is ideal for audiophiles seeking a combination of high fidelity and elegant, slim-profile design.