Grimm Audio LS1 and LS1s subwoofer

Grimm Audio is based in the Netherlands, and is the brainchild of four prominent audio engineers. It has forged a strong reputation with products based on tested scientific principles. The LS1 and its partner subwoofer, the LS1s, represent a first foray into loudspeakers, and are the end result of a rigorous development process.


It’s immediately clear the LS1 is something different: black (custom colour schemes are available), and standing 1.44m tall, semi-cylindical legs support a flat 14-litre sealed enclosure (47x36x16cm HWD) containing two SEAS drivers, an 8-inch woofer and a 1-inch tweeter. System electronics reside in one of the legs and include 48/76-bit DSP, a high-quality digital clock based on Grimm’s standalone CC1, A/D and D/A converters (both analogue and AES digital inputs are available), and two 180 watt Hypex NCore Class D amplifiers. The subwoofer measures 17x34x34cm with the same rounded-corner profile as the LS1’s baseplate. It fits snugly at the bottom of the legs with its 9-inch (23cm) Peerless driver facing upwards and is powered by a 400-watt Class D amplifier.

Controlling the system is a USB interface and software for Mac or PC. In addition to level management the software offers a number of features of interest to professional users, such as left/right swap, the ability to listen to the Side signal on its own and even ‘Ported’ and ‘Small’ speaker emulation modes. An optional wood-ended physical remote with a level wheel and display completes the setup; the ‘press’ action on the wheel can be set to mute or dim playback. The remote provides another two AES inputs in addition to the standard one, so I had my workstation, reference player, and PC’s outputs available and could offset their relative levels if required. Another useful aspect of the remote is being able to set the metering at one’s preferred reference volume, making level-matched comparisons very easy. I’m told there are plans for a ‘pro’ version, making more functions available in hardware, a development that could remove the need for a separate monitor controller.

In Use

The LS1 requires some assembly from new, although separating the main elements in transit makes sense with well-designed packaging protecting what is, after all, a sizeable investment. Taking my time, I needed about an hour to attach the legs to the two speakers’ enclosures, add baseplates and leg trims, position the subs and wire everything up – having checked the analogue input worked as expected, I stayed digital throughout the review period. Although placed as normal at the outer points of a listening triangle, Grimm recommends an angle across the front of the user at 45º instead of the usual 30º to reduce room effects. This looks unusual (and of course conventional positioning is also possible) but it worked for me and sounded best in my studio.

After a day of auditioning and run-in time I took the plunge by using the Grimms for all mastering work arising during their residency, debunking conventional wisdom that two-way speakers are not an ideal solution with possibly the clearest and least hyped presentation I’ve heard. I had that feeling of an open window into sound, across a wide range of music styles.

There is clever DSP in the main cabinet crossover between drivers, and (unusually) I was unable to hear the transition point. This promotes an extraordinarily well-balanced top-to-bottom staging of audio, and it’s been said the LS1 sounds in some ways like an electrostatic speaker but with none of the flaws. Don’t get the idea it just makes everything sound good though: while somehow remaining immensely listenable, you’re left in no doubt as to what is and isn’t working in a mix.

Switching in the subs from the remote application extends low frequencies down to 20Hz and increases the available headroom, crossing over at a DSP-controlled 70Hz. Although this works well, it’s likely to be most useful in larger spaces than mine: in my 30m2 room at typical mastering volumes I was happy with the LF provided by the LS1 pair alone and, perhaps surprisingly, didn’t feel a lack of low end resolution despite a gentle rolloff below about 40Hz. The LS1 is protected by an excursion limiter (as with other functions this flashes an LED in the dot of the i of ‘Grimm’ in the cabinet’s logo, a neat touch), and I had to increase gain by about 20dB over my usual reference level before it engaged, and a few dBs more with the subs. Bearing in mind that I was testing with bass-heavy material, I can safely say the system plays loud enough for the majority of users.


With or without a subwoofer, the LS1 is a special loudspeaker. Quality costs, as usual, but you’re getting a number of facilities (amplifiers, converters and monitor control) that might require additional outlay with a more conventional setup. In over a decade of reviews for this magazine I’ve heard only one system to rival the Grimm, and that was more than twice as expensive: I’ll be genuinely sad to part ways at the end of this particular loan period, and would urge anyone looking for a true audio monitor to give the Grimm Audio LS1 a listen.

Review: Nigel Palmer