Marshall Kilburn III Review: A Classic Rock Bluetooth Speaker

What’s wild about this jump in stamina is that it’s disproportionate to the battery’s capacity. The Kilburn II ships with a 5,200 mAh cell, while the new model is only about 5 percent bigger: 5,500 mAh. Clearly, some big efficiencies have been gained. In fact, Marshall is so confident about the Kilburn III’s power reserves that it now lets you charge your devices from the speaker’s USB-C port.

A word of caution: The direction of the charge is dependent on the Kilburn’s status. When the speaker is powered on, charging flows outward to phones and other accessories. However, when the power is off, the speaker will draw power from them. The Kilburn won’t automatically power off when a USB device is connected, but if you turn it off manually (or connect a device while it’s off), your phone will drain instead of charging.

Marshall app via Simon Cohen

To help extend the battery’s lifespan, you can enable up to three preservation schemes in the Marshall app: setting the maximum charge to 90 percent, adjusting the charging speed in hot and cold conditions, and capping charging speed whenever connected to power. When the battery eventually dies, an access door on the bottom of the cabinet makes it easier to replace. Previously, you’d need to disassemble the entire speaker.

Unfortunately, Marshall doesn’t include a 30-watt USB-C PD power adapter, which you’ll need to quick-charge the Kilburn (20 minutes gives about extra eight hours of playtime) or to fully recharge the speaker (about three hours). Maybe that’s because Marshall doesn’t want you to use such a powerful charger as your main power source, and actually warns against it in the app.

And yet, less powerful chargers will slow the process considerably; a typical 5-watt charger could take up to 22 hours for a full recharge. A 10-bar LED battery gauge on the top panel does make it easy to keep tabs on how things are going, so you can see when it’s really slow.

Audio Quality

This speaker sounds great for its size and its price. It’s not going to rock your house party single-handedly (it gets decently loud but not wake-the-neighborhood loud), but it has a degree of bass resonance that I normally associate with larger units, and decent balance through the frequency range. Distortion is very well controlled; even with volume maxed out, Billie Eilish’s bass-tastic “bad guy” only hinted at being too much for the system. I noted a small loss of detail in the upper-mids, combined with a slightly harsh presentation of highs. It was most noticeable with strong female vocalist tracks like Adele’s “Skyfall.”

Marshall app via Simon Cohen

Thankfully, there are plenty of tweaks available to generate a mix that suits your tastes. Within the silver-icon Marshall Bluetooth app (not to be confused with the gold-iconed Marshall Wi-Fi app), you’ll find five EQ presets (the default Marshall tuning plus four more), plus the ability to create one of your own using the five-band equalizer. The “M” button on the Kilburn III’s top panel lets you swap between the Marshall tuning and one other preset of your choosing.
If these aren’t enough, you can crank the speaker’s dedicated bass and treble knobs for even more range (or just use them on their own).

Marshall’s driver arrangement, which puts a full-range transducer on the front and back, makes it more versatile in terms of placement than traditional front-firing speakers. Marshall’s claim of full, 360-degree sound is accurate: put the Kilburn III in the middle of your space and there isn’t a bad seat in the house. On the other hand, putting it in a corner or near a wall will affect the sound, so there are a few placement adjustments in the app that can help the speaker compensate, to a degree.

Only Sort-Of Stereo

Photograph: Simon Cohen

The brand’s claim of “stereophonic” audio should be taken with a grain of salt. The Kilburn III does indeed reproduce both left and right channels—thus, technically, it’s stereo—but you’re not going to experience true stereo separation. Instead, you can think of it as a single point source of sound that has a very expansive footprint.