Полочная акустика — Graham Audio LS8/1

The LS8/1 is a three-driver stand-mount from Graham Audio, the British company that builds licensed BBC monitors and BBC-inspired designs in collaboration with engineer Derek Hughes. It is Graham's take on the classic format of an 8 in bass driver in a 2 cubic foot box, used by many designers over the years, including Hughes and his father Spencer, who designed the BBC LS3/6. It uses modern drivers in a traditional thin-wall cabinet.

Key specs that matter

It uses a 200 mm SEAS mid/bass driver, a 25 mm SB tweeter and a 19 mm SEAS super tweeter, crossing over at 3.5 kHz and 14 kHz, in a ported enclosure. Response spans 45 Hz to 20 kHz (+/-3 dB), sensitivity is 87 dB at 2.83 V and nominal impedance is 8 ohms. Maximum output is 100 dB for a pair at 2 m, and recommended amplifier power is 50 to 250 W. The cabinet is 635 mm tall and 300 mm square in plan, and it weighs 17 kg.

Engineering and use context

The cabinet follows the BBC thin-wall principle, with birch ply under hand-matched real wood veneers, and custom paint finishes are offered to order. The front and rear panels are screwed rather than glued, which decouples them and eases later maintenance. Rather than making the walls as stiff and heavy as possible, it uses thin birch plywood panels that are critically damped, shifting their resonances away from the critical midrange and lowering their stored energy. Designs of this family were among the first to use plastic diaphragms for the mid/bass, an innovation at the time. Graham Audio addresses the weaknesses of earlier models of this type, some of which suffered limited power handling or bass responses unsuited to domestic rooms, using modern drive units with greater power handling. The 19 mm super tweeter takes over above 14 kHz, extending response to 20 kHz while the main tweeter covers the upper midrange. A Derek Hughes Signature Edition was produced in a limited run of 100 pairs. Graham Audio supplies dedicated stands, and the speaker is designed to be used on them away from walls. Graham Audio manufactures its thin-wall cabinets in the UK, as it does for its licensed BBC models. The design suits owners who want a BBC-derived design in a larger box than the LS5/9. In the UK a pair cost GBP 4,712, and in the USA USD 9,700.

Pairing

The benign nominal load works with a wide range of solid-state and valve amplifiers within the recommended power range, and the output capability suits rooms of 15 to 30 m2.

Alternatives

Graham Audio's LS5/9 is the licensed BBC two-way monitor with a 200 mm polypropylene driver and a 34 mm Audax tweeter.