Напольная акустика — ProAc K3

The K3 is the most compact floor-standing K Series tower made by ProAc, the loudspeaker company based in Brackley, Northamptonshire. Rather than using a separate midrange unit, it relies on a pair of Kevlar bass drivers developed specifically for this model, placed either side of a centrally mounted ribbon tweeter in a K-type cabinet. The range also holds the K6, K6 Signature and K10 towers, and ProAc added the stand-mounted K1 after the floor-standing models proved successful.

Key specs that matter

The published figures give a nominal 4 ohm impedance and a sensitivity of 89 dB linear, measured with 1 watt at 1 metre. Frequency response is listed as 25 Hz to 30 kHz. ProAc recommends amplifiers between 10 and 250 watts. The cabinet stands 1073 mm tall, is 210 mm wide and 340 mm deep, and each speaker weighs 42 kg. Two 165 mm bass and midrange units work with one ribbon tweeter.

Engineering and use context

ProAc says the Kevlar driver was engineered for the K3 so that it could reach further up into the midrange than a conventional woofer, and it carries a phase plug in its centre, which ProAc credits with improving dispersion. Because these two cones cover both bass and midrange, the crossover has only one hand-over point to the ribbon, and ProAc states that a dedicated network was drawn up for the K3 so that the woofers mate cleanly with that tweeter. The ribbon uses a diaphragm said to be as light as a human hair, backed by a damped chamber and driven by an alnico magnet. The crossover parts sit on a dual layer printed board, and the internal cabling is multistrand oxygen free copper from ProAc. Six standard veneers are available, namely Walnut, Silk White, Natural Oak, Mahogany, Cherry and Black Ash, and three special veneers - Ebony, Rosewood and Liquidambar - are built to order for an added charge. The featured sample on the maker's page is finished in Cherry. The cloth grille is crimplene, chosen to be acoustically transparent, and a magnetic grille version exists for selected veneers.

Pairing

Twin sets of terminals on the rear accept separate cable runs for bi-wiring, or bi-amplification using one amplifier channel for the woofers and another for the tweeter in each cabinet. ProAc's broad power recommendation admits low-powered valve designs as well as large solid-state amplifiers.

Alternatives

The ProAc K6 is the next tower in the K Series, adding a 50 mm soft dome midrange with a machined aluminium horn to two Kevlar bass units and a ribbon tweeter.