Bookshelf Speakers — ProAc K1

The K1 is the only stand-mounted model in the K Series from ProAc, the loudspeaker maker based in Brackley, Northamptonshire. ProAc explains that the success of the K Series floorstanders led to requests for a stand-mount version, and the K1 followed after years of research and development. It borrows the Kevlar cone and ribbon tweeter used across the K range, while the cabinet, the bass unit and the tweeter were each modified to suit a smaller box placed on a stand.

Key specs that matter

The K1 is a two-way, in which one 165 mm (6.5 in) Kevlar coned unit handles both bass and midrange, with a ProAc ribbon tweeter above it. ProAc quotes a frequency response of 28 Hz to 30 kHz, sensitivity of 90 dB linear for 1 W at 1 m and a nominal impedance of 8 ohms, and it lists amplifiers from 10 W to 150 W as suitable. The cabinet stands 569 mm high, 210 mm wide and 401 mm deep.

Engineering and use context

The ribbon in the tweeter is lighter than a human hair, and the unit uses rear chamber damping and an alnico magnet. The enclosure follows the K design with vent porting, the same loading approach as the floor-standing members of the series. The crossover sits on a dedicated dual-layer circuit board with ProAc multistrand oxygen-free copper cable throughout, and it is split so the owner can bi-wire or bi-amplify the speaker. The grille is acoustically transparent crimplene, and magnetic grilles are offered with certain finishes. ProAc developed a dedicated stand for the K1, sold separately, that is 500 mm tall with a 320 x 190 mm top plate and weighs 15 kg each. The standard finishes are black ash, mahogany, cherry, natural oak, silk white and walnut, while liquidambar, rosewood, ebony and tamo ash veneers are made to order at extra cost.

Pairing

The high sensitivity and the easy nominal load mean the K1 does not require a high-current amplifier, and the low end of ProAc's recommended range allows a modest valve design as well as larger solid-state units. The split crossover leaves room to add a second stereo amplifier for the bass and treble sections later, or to run two separate cable runs from a single amplifier. Within the K Series the K1 shares its tweeter type with the K3, K6, K6 Signature and K10 floorstanders, which keeps the treble units consistent across the range.

Alternatives

The ProAc Response D2 is a stand-mounted two-way from the Response Range with a glass fibre wave cone, offered with either a dome or a ribbon tweeter.