PreSonus Eris 3.5 BT

These remarkably affordable speakers raise the bar for ultra‑compact monitoring.

In recent years, we’ve heard a number of tiny desktop monitors that have had us looking under the desk to see if there’s a sub. Compact speakers from Genelec, IK Multimedia, KRK and others are now joined by the very affordable PreSonus Eris 3.5 BT. As you can probably guess from the name, the speaker has a 3.5‑inch bass driver, in this instance passively crossed over at 2.8kHz to a one‑inch, silk‑dome tweeter. The woofer cone is a woven composite material. All the electronics reside in one of the speakers, with a two‑core link cable to feed the other. Included in the price is a special edition of PreSonus Studio One, plus the Studio Magic collection of plug‑ins, loops, virtual instruments and effects.

The cabinets are made from MDF with a fairly conventional black plastic foil finish, and the baffle is sculpted around the tweeter and woofer openings. Overall, the cabinets measure 140 x 200 x 160mm, and on the front panel of the master speaker, there’s a power switch, volume control and multi‑colour power/status LED strip. Other controls and connections are on the rear panel, along with a circular rear tuning port.

There’s a choice of input connector, with RCA phonos and quarter‑inch balanced TRS jacks at the rear plus a stereo mini‑jack aux input on the front. An input impedance of 10kΩ is quoted. There’s also a TRS headphone output, which mutes the speakers when in operation. Then, of course, there’s Bluetooth, so you can play music from a Bluetooth device (supporting Bluetooth 5.0) without the need to plug anything in. A pairing button on the rear panel gets you going, and pairing with my old iPhone 7S took just a few seconds. This doesn’t mute the other inputs. The Eris 3.5 is also available in a non‑Bluetooth version, which is even more affordable.

Power Up

We’re used to seeing studio monitors with power amp specifications above 100 Watts, but here we have just 25 Watts of Class‑A/B amplification for each speaker. Don’t let that put you off, though! The peak SPL at one metre is quoted as being 100dB, and the frequency response as 80Hz to 20kHz, though with no ‘dB down’ limits specified, this last spec doesn’t convey much useful information. The amplifiers are fitted with output current limiting and thermal protection, and are designed to avoid switch on/off thumps. A subsonic filter keeps out excessively low frequencies, and there’s tonal adjustment courtesy of low‑ and high‑frequency tuning controls (±6dB at 100Hz and 10kHz) on the rear panel, but in my small office/studio, the speakers sounded just fine with everything set flat.

The punchy low end from these tiny speakers is nothing short of astonishing...

On paper, then, these might look like ‘me too’ speakers, but once you hear them you’ll find that their performance is anything but average. The punchy low end from these tiny speakers is nothing short of astonishing, and when used as part of a typical desktop system, set up maybe 70cm from the listening position, there’s no shortage of clean volume. The midrange carries vocals well and the highs come over as crisp and articulate without seeming harsh or aggressive. All ported speakers exhibit some low‑frequency overhang, but this didn’t seem excessive when running my usual selection of test material.

Inevitably the Eris E3.5 BTs can’t rival full‑size, full‑price studio monitors in all respects, but given their small size and surprisingly low cost, I really can’t fault them, and if I had to do mixes in my office rather than in my studio, I’d be very happy to work with them. It seems that serious compact monitoring really has come of age over the past few years.