Напольная акустика — Audio Note AN-E Ltd

The AN-E Ltd is the field-coil branch of the AN-E loudspeaker family from Audio Note (UK), a two-way reflex design that keeps the standard AN-E cabinet but replaces permanent magnets in both drive units with electromagnets fed from an external power supply. Chief designer Andy Grove led the work. The Ltd range comes in six versions, and the AN-E/SPx Ltd is the least expensive of them, listed in the UK at GBP 46,428.57 per pair and in the US at USD 65,000 per pair with power supplies included. Drivers and supplies are made in-house in the UK, while cabinet construction, driver matching and final assembly take place in Austria.

Key specs that matter

A 25 mm SEAS silk dome tweeter and a 200 mm SEAS hemp-cone mid/bass unit with a silver voice coil both use field-coil motors. Nominal impedance is 6 ohm and sensitivity for the SPx Ltd is 97 dB. Audio Note quotes 18 Hz to 23 kHz within 6 dB, measured in room, and asks for at least 8 W RMS per channel, with 150 W unclipped RMS as the upper limit. Each cabinet stands 790 mm high, 360 mm wide and 270 mm deep and weighs 29 kg in internal-crossover form, against 23 kg for the permanent-magnet AN-E models, whose minimum amplifier rating is 7 W.

Engineering and use context

For the magnet structures Audio Note worked with a foundry in the Black Country to develop ferritised, heat-treated castings with pure-iron pole pieces. The external supply uses an in-house mains transformer and stabiliser circuitry derived from the filament supplies of the M3 to M10 preamplifiers. Passive supplies were tried during development and dropped because they did not cope with back-EMF from the drivers or with fluctuations in the mains. The crossover is hard-wired with simple first-order slopes, using hand-made resistors on phenolic formers, air-core inductors and bipolar or polypropylene capacitors. Signature and Sogon versions move the crossover into an external box. The cabinet is birch plywood with a real wood veneer in high gloss, offered in Olive, Palisander, Apple Walnut, Makassa-Ebony or Black, and the wide front baffle is meant to act as a virtual wall that evens out dispersion. The supply and crossover boxes have aluminium or black fascias, and custom fascia colours cost extra.

Pairing

The high sensitivity and moderate load put the speaker within reach of low-powered single-ended triode amplifiers built around 300B or 2A3 valves, and larger valve or transistor amplifiers can be used up to the stated ceiling. Mains outlets are needed for the two field-coil supplies.

Alternatives

The Audio Note AN-E/SPx AlNiCo uses the same cabinet size with permanent AlNiCo magnets in place of field coils.