Напольная акустика — Zu Audio UNION 6

The Union 6 is a high-efficiency floorstanding loudspeaker hand built in the USA by Zu Audio and presented in 2022 as the base model of the Union series. It is a direct radiating design with a nominal 8 ohm impedance, and Zu quotes a starting price of USD 3,500 for a matched pair, with an order-to-ship time of five to seven weeks depending on finish.

Key specs that matter

Zu lists bandwidth as 30 Hz to 22 kHz and efficiency as 99 dB SPL at 1 watt and 1 metre. Maximum program level is given as 120 dB-Z on a slow meter. Maximum music input is 150 W full range, rising to 300 W with a 12 dB per octave high-pass at 50 Hz and to 450 W with the same slope at 80 Hz. Each cabinet measures 30.5 x 30.5 x 91.5 cm and weighs 27 kg.

Engineering and use context

Sound comes from Zu's own ZuCX-ND-8, a 10.3 inch coaxial full-range unit with a paper and carbon nanotube cone and an under-hung 2 inch voice coil on a former of paper and Kapton, with an Eminence UAPT50-3 supertweeter mounted coaxially in front of it. The full-range driver runs with no crossover or filter at all. Only the tweeter has a filter, a mono-pole high-pass using a single 1.0 uF ClarityCap MR capacitor as its sole element. Internal wiring uses Zu Mission Mk.II cable with silver-plated connections. The cabinet is built of North American composite wood with either real wood veneer or an epoxy skin, in Satin Black and Satin White as standard, plus Rustic Hickory, Ruby Red, Electric Blue, American Walnut and custom options at extra cost. Speaker connection uses binding posts that accept spades, banana plugs and bare wire up to 4 AWG, wired in parallel with a speakON NL8 socket for Zu's own B3 cable. Oval-ended stainless steel set-screw footers are installed, and 38 mm carpet spikes come in the box. Zu states the cabinet can stand as close as 5 cm from the wall behind it, and covers materials and workmanship with a five-year limited warranty.

Pairing

Zu grades amplifier power by the level a listener wants. Between 2 W and 15 W it expects low to moderate levels, 15 W to 50 W reaches moderate to very loud levels, and above 50 W, up to the maximum music input, covers very loud playback. That range opens the door to small single-ended valve amplifiers and also more powerful transistor amplifiers, and a high-pass filter ahead of the amplifier raises the usable power as listed above.

Alternatives

The Zu DW6 is a lower-priced floorstanding loudspeaker from Zu Audio that also combines a single full-range driver with a supertweeter.