Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker


The BenQ treVolo ($299) is an electrostatic compact portable Bluetooth speaker with a unique set of components. It comes from BenQ, a company known mostly for projectors and monitors — treVolo is the company’s only speaker. The name “treVolo,” roughly translated from Italian, means “three flights.” We let BenQ’s high-end speaker spread its wings; let’s see if it can soar.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

At almost three pounds, the treVolo is probably a bit heavy for frequent portable use, though it does come with a built-in rechargeable battery if you’d like to use it in that way. Thankfully, this heft can mostly be attributed to high-quality design. Almost the entire housing is made from a single piece of aluminum, broken only by a series of holes for buttons and speaker ports, each chamfered with a polished gold edge. Buttons are appropriately clicky, and plastics are stiff and textured for an overall premium feel. In a world full of light-but-cheap plastic portable speakers, the treVolo justifies its weight with quality.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

The treVolo is a versatile device. While most users will pair their phones for Bluetooth playback, we highly recommend that you also try a clean line signal from a high-quality source like a MacBook Pro or dedicated digital audio player. The treVolo also has an onboard DAC; when connected to a Mac or PC over USB, the treVolo will be recognized as an audio device and handle the digital to analog conversion inside the unit, away from the noisy electrical environment inside your computer. A line out jack is also present on the treVolo, but we were hard-pressed to think of a real life use for it.

Bluetooth pairing was simple enough, and volume controls are thankfully linked to those on your device. Controls on the unit are sparse, with only volume and play/pause buttons included. BenQ offers an iOS app that lets you check the treVolo’s battery level and switch sound profile; functionality is limited, but the app is free, so we can’t complain.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

Like any aircraft, the most interesting parts about the treVolo are its wings. Instead of the dynamic speakers we most often see — which use magnets to move a circular cone back and forth — the treVolo uses a pair of electrostatic speakers. Instead of a cone, these speakers use an extremely thin membrane coated in metal and suspended between two electrically charged metal plates. Changing voltage in the metal plates forces the membrane to move back and forth, generating sound. Electrostatic speakers are known for excellent reproduction of mids and highs in a very thin form factor. This allows the treVolo to offer essentially the best of both worlds. When open, each “wing” offers a large surface area for music reproduction; when closed, the 5mm thin speakers fold almost completely flat.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

Since electrostatic speakers can’t move enough air to excel at bass reproduction, the treVolo also packs a pair of two-inch woofers to complement the sound. These are housed in a chamber with two passive diaphragms to further boost bass response. Though imaging felt a little small and vocals sounded a little recessed in “Pure” mode, the overall result is very good. The treVolo plays rich, full, clear, and detailed sound that we very rarely hear in such a compact package. To our knowledge, this is the first time electrostatic speakers have been used in such a small unit; we’re glad that BenQ took the risk.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

Our extensive testing of the treVolo revealed some minor limitations that keep the treVolo from being an ideal all-around speaker. Despite its impressive music reproduction, we found that the treVolo’s sound is extremely sensitive to positioning and room size. Too close, and the sound changes dramatically even a few inches off-center. Too far, and the treVolo felt underpowered. We found that the treVolo excelled in medium rooms at medium distances, like an office or kitchen. To be fair, BenQ is forthcoming with this information, acknowledging that electrostatic speakers are somewhat directional, and that a listening distance of 10-12 feet is optimal.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

Though we liked the fact that the treVolo can handle Bluetooth, Line, and USB inputs, we were disappointed to learn that the only way to switch sources is to connect or disconnect cables. If a line or USB source is connected, no sound will play over Bluetooth. If you have the treVolo on your desktop connected to your Mac or PC via USB, you’ll have to reach around back and disconnect your USB cable if you want to play something from your phone. In a device that really needs to be at some distance from the listener to sound right, we would have appreciated a more convenient way to switch inputs.

Review: BenQ treVolo Bluetooth Portable Electrostatic Speaker

The treVolo’s Bluetooth functionality also fell slightly short of BenQ’s promises. In our testing, Bluetooth started to hiccup at less than the advertised 30 feet, but was completely functional within the medium-sized room that this speaker seems intended for. Speakerphone, while functional, was underwhelming at best. Sound was muffled on both ends, and friends reported that we sounded muffled on the other end. Since the treVolo’s microphone is mounted on its base, tucked under the front speaker grille, this issue might be resolved by raising the unit a few inches off your desk or bookshelf. In any case, we recommend that you stick with music, where the treVolo really shines.

Overall, it’s clear that BenQ put a lot of thought into the treVolo. BenQ has packaged different technologies together that complement each other and present a truly unique offering, and we applaud the effort. Living with the treVolo revealed some limitations, but these don’t detract from our recommendation. Rather, they should serve to focus your purchase decision — if you need to fill a large space with sound or switch inputs quickly, the treVolo isn’t for you. But other listeners should be pleased with this interesting speaker, and it earns our general recommendation.

Table of Contents

Our Rating


Company and Price

Company: BenQ

Model: treVolo

MSRP: $299

Compatibility: Bluetooth iPads, iPhones + iPods

Photo of author

Guido Gabriele

Contributing Editor