Other devices — Pro-Ject Wireless Box E

The Wireless Box E is a mono streaming amplifier from Pro-Ject Audio Systems, the company founded in 1991 by Heinz Lichtenegger in Mistelbach, Austria, which makes turntables and compact Box Design electronics. It belongs to the E line, the entry level of that Box Design range. The unit plugs straight into the terminals of a passive loudspeaker with 4 mm banana plugs and turns it into a wireless active speaker, with no separate amplifier or long speaker cables. A stereo pair needs two units.

Key specs that matter

Output is 25 W into 8 ohms and 50 W into 4 ohms at 1% THD. Frequency response covers 20 Hz to 20 kHz within -1.5 dB into 4 ohms. Signal-to-noise ratio is 96 dB, or 100 dB A-weighted, THD stays below 0.12% at 5 W into 4 ohms and channel separation is -67 dB at 10 kHz. Streaming runs on WiiM OS, with dual-band Wi-Fi 802.11 a/b/g/n/ac and Bluetooth 5.0 with SBC and AAC. Each unit is powered by an external 22 V/1 A DC supply and uses less than 0.5 W in standby. An aluminium front panel sits on a metal chassis, and Pro-Ject gives a two-year warranty.

Engineering and use context

Since the amplifier is mounted on the speaker's own terminals, there is no cable run from an amplifier to each speaker, although every unit still needs its own power adaptor. Each Wireless Box E amplifies one channel, so the left and right signals reach the pair separately over the network. With Pro-Ject's True Wireless Receiving function, the units play audio sent from compatible sources such as the Stream Box E streamer or the Uni Box S3, which means a turntable, CD player or digital source connected to one of those hubs can play through the wireless speakers. Current WiiM streaming products can also send audio to them. WiiM OS handles streaming from services such as TIDAL, Spotify and Qobuz, multi-room grouping with other current Pro-Ject and WiiM streamers and control through the Pro-Ject Home app. The unit is optimised for Pro-Ject passive loudspeakers, on which it fits directly. For other brands, where the terminals are hard to reach or spaced differently, Pro-Ject offers the optional Connect it LS Flex extension cable.

Pairing

A pair of Pro-Ject bookshelf speakers with two Wireless Box E units makes a complete streaming system. Adding a Stream Box E or Uni Box S3 brings wired sources into the wireless setup.