Напольная акустика — KEF Q750

The KEF Q750 is a floorstanding loudspeaker from the 2017 Q Series, which KEF presented as the eighth iteration of the range and which included three towers - the Q550, Q750 and Q950 - plus the Q150 and Q350 bookshelf models and the Q650c centre channel. The Q750 sits in the middle of the floorstanding trio. Launch prices were USD 750 each and GBP 1,150.

Key specs that matter

KEF specifies the Q750 as a 2.5-way reflex loaded design. A 165 mm (6.5 in) Uni-Q driver with a 25 mm (1 in) vented aluminium dome tweeter at its centre covers the midrange and treble, a separate 165 mm aluminium low frequency driver adds bass, and two 165 mm aluminium auxiliary bass radiators (ABR) complete the driver set. The crossover frequency is 2.5 kHz. Response is 48 Hz to 28 kHz within plus or minus 3 dB, and the free field range extends to 42 Hz at minus 6 dB. Sensitivity is 88 dB with maximum output of 111 dB. Nominal impedance is 8 ohm but drops to a 3.8 ohm minimum, and the amplifier range is 15 to 150 W. The cabinet measures 923 x 210 x 306 mm without its plinth and 977 x 323 x 310 mm with it, and weighs 16.5 kg.

Engineering and use context

In this arrangement both the Uni-Q unit and the lower woofer work in the bass, while only the Uni-Q driver continues above that into the midrange. Rather than a port, the low end is reinforced by the two passive radiators, which for 2017 got a new surround and rear suspension. The Uni-Q array gained a damped tweeter loading tube aimed at the lower treble, and the crossover received a new lower-distortion inductor for the bass section. The woofers across the floorstanding models were updated with new roll surrounds, spiders and paper cone materials. Inside the cabinet a separate sealed chamber houses the coaxial driver, and the bass-only unit rolls off from 200 Hz. The front baffle is 35 mm MDF, with 15 mm MDF used for the sides and rear, and all drivers and radiators mount flush with the baffle. Outriggers with spikes are included, the rear carries one set of speaker terminals, and the warranty covers five years. The vinyl finish came in Satin Black or Satin White, and magnetic grilles were sold separately.

Pairing

Since impedance drops well under the nominal rating, a suitable amplifier has to handle those dips, while the modest lower power limit leaves room for modest integrated amplifiers. For a matching surround system the same generation offered the Q650c centre and Q50a surround models.

Alternatives

The KEF Q950 sits above the Q750 among the 2017 Q Series floorstanders, priced at USD 900 each at launch.