Напольная акустика — Graham Audio LS5/5F

The LS5/5F is the floorstanding derivative of the Graham Audio LS5/5, the company's revision of a three-way BBC monitor first described in 1967. The BBC used that design for classical music monitoring and later relied on it to calibrate microphones. Graham introduced its updated LS5/5 in 2019, and the F version keeps the same set of drive units but adds a bass chamber beneath the main cabinet. In the USA it cost USD 16,999 per pair in cherry or oak and USD 18,999 in walnut.

Key specs that matter

It uses a 300 mm long-throw bass driver, a 200 mm midrange and a 25 mm soft-dome tweeter in a reflex-loaded, thin-wall damped enclosure, with crossover frequencies of 400 Hz and 3.5 kHz. Graham quotes 35 Hz to 20 kHz within 2 dB, 88 dB SPL for 2.83 V at 1 m and an 8 ohm nominal impedance. Maximum output is above 104 dB for a pair at 2 m. The cabinet is 36 cm wide, 111 cm tall and 48 cm deep, and each speaker weighs 46 kg.

Engineering and use context

Compared with the stand-mount model, the crossover is modified in the bass region and an extra enclosure is added underneath. This lower chamber acts as extra acoustic volume for the bass driver, and Graham states that it yields roughly 7 dB more output at 20 Hz. The upgraded magnets, drivers, glue and crossover components of the 2019 revision give 10 dB more power handling than the BBC original, which had its own built-in 25 W amplifier. A tweeter level control on the front panel changes the treble output by 1 dB either way. The bass and midrange cones sit behind slots cut in the baffle, a BBC technique that widens their dispersion near the top of their operating range and smooths the transition to the tweeter. Inside, Rockwool provides air damping in the thin-wall cabinet. Veneers are hand-matched, magnets hold the grille without visible fixings, and buyers can choose cherry, oak, walnut, rosewood, macassar or ebony. Because the woofer, midrange and tweeter are shared with the LS5/5, the two models differ mainly in low-frequency extension, height and weight.

Pairing

Graham gives a recommended amplifier range of 50 to 250 W, and its middling efficiency points to solid-state amplifiers or high-output valve designs. Unlike the LS5/5, this version is used without separate stands.

Alternatives

The Graham LS5/1 is a larger-driver floorstander in the Graham range that combines a 380 mm slot-loaded woofer with twin tweeters in a two-way layout.