Review: Grimm LS1be + SB1 – Active speakers with subwoofer

Review: Grimm LS1be + SB1 - Active speakers with subwoofer - It is a high-quality, neutral, and transparent audio solution with roots in professional studio applications


The LS1 speaker from Grimm Audio, available through, is a classic in the world of loudspeakers due to its unique design. In this comprehensive review, we will delve into the various aspects of the Grimm LS1be plus SB1 subwoofer speaker system, providing a detailed analysis of its design, technology, sound performance, and overall suitability.

Design and Acoustic Philosophy

The LS1 speaker system’s design is distinctive and unconventional. It stands wide-legged and hides its subwoofers, creating a visually captivating presence. Grimm Audio offers several LS1 variants, and we are examining the LS1be plus SB1 subwoofer configuration, the flagship model among them. While this top-of-the-line setup comes with a premium price tag of around 38,000 euros, more affordable options exist for smaller rooms, such as the LS1a, priced at 14,750 euros per pair. Despite the differences in price and features, all LS1 models share the same basic acoustic design.

Fully Active and Streamlined Setup

The LS1 series of speakers are fully active, meaning they come equipped with built-in amplifiers and digital-to-analog converters (DACs). This design promotes a minimalist and realistic setup, where you can simply add a streaming bridge, such as the Grimm MU1, to complete the audio system. Alternatively, you can use a laptop or other audio sources to drive the LS1 speakers.

Acoustic Engineering

A unique feature of the LS1be is its wide baffle design, which serves both an acoustic and aesthetic purpose. This design addresses the baffle step issue by moving it into a frequency range where human ears struggle to differentiate between direct and indirect sound. Additionally, the side-mounted, curved stilts help increase the effective baffle width and reduce edge diffraction, enhancing sound quality. The LS1be’s design carefully considers the placement of its components, such as the tweeter, to optimize its acoustic performance. These design choices are driven by the principle of “form follows function.”

Subwoofer Integration

The LS1be-SB1 system operates as a three-way speaker configuration with crossover frequencies set at 70 and 1550 Hertz. It employs 4th-order Linkwitz-Riley filters and digital signal processing (DSP) for precise corrections. Grimm Audio takes a unique approach by emphasizing minimal DSP usage and prioritizing acoustic solutions whenever possible.

The SB1 subwoofers, with their 10-inch Dayton drivers, offer an innovative feature called Digital Motional Feedback (DMF). This technology uses an acceleration sensor on the woofer’s membrane to detect and correct deviations from the desired response, resulting in a 30 dB reduction in distortion levels and exceptionally clean bass reproduction.

Electronics and Calibration

The LS1be integrates its electronics, including amplifiers, DSP, clock, and DAC, within one of its legs. This arrangement isolates them from fluctuating voice coil magnetic fields and acoustic interference, enhancing protection against microphone pickup. The speaker legs are filled with insulating material to minimize resonance, though some optimization may be possible in this regard. Additionally, the LS1be employs Hypex NCore Class D amplifier modules, designed by Bruno Putzeys, who is also involved in the development of the LS1.

Calibration is a crucial aspect of the LS1be’s performance. Each speaker undergoes Computer Aided Calibration (CAC) to ensure individual calibration to an internal reference, using minimally invasive filters. Grimm Audio believes in using DSP sparingly and with a focus on preserving the sound quality.

LS1 Models and Variants

Grimm Audio offers three LS1 models, with the LS1v2 considered the standard variant. The LS1a is a more affordable option with some simplifications, while the LS1be, our test subject, features an exclusive tweeter developed in collaboration with Seas, a premium component selection, and improved electronics. These variations cater to different budgets and preferences.

Connectivity and Control

The LS1’s connectivity options reflect its studio origins, offering analog XLR inputs, AES/EBU input, control RJ45 input and output, and a link to the optional subwoofer. Notably, it lacks consumer-oriented features like Bluetooth, HDMI ARC, Toslink, or S/PDIF coaxial inputs. To control the LS1, Grimm Audio provides the LS1 Remote software, which allows adjustments to inputs and volume. It is advisable to install this software for comprehensive control, as the LS1 does not have physical controls on the speakers themselves. There is also an option for the LS1r Remote, a wired remote control, or the integration with the Grimm MU1 player/server.

Sound Performance

In terms of sound performance, the LS1be-SB1 system offers tonal neutrality and remarkable resolution across the frequency spectrum. Its bass reproduction is characterized by clarity and precision, even at low listening volumes. While it may not deliver overwhelming bass quantity, it excels in dynamics and can achieve high sound pressure levels. Transients and dynamics are handled with immediacy and liveliness.

Sound Test and Performance

The sound performance of the Grimm LS1be plus SB1 subwoofer system is characterized by several key elements, including tonal neutrality, exceptional resolution, dynamic capability, spatial presentation, and versatility across various musical genres. Let’s delve into these aspects in greater detail:

1. Tonal Neutrality: The LS1be-SB1 system, at its core, aims to provide a transparent and faithful reproduction of audio content. It does not impose any coloration or tonal bias on the sound. This neutrality is a fundamental quality for studio-grade speakers, ensuring that the listener hears the music as it was originally recorded without any added warmth or brightness. While this neutrality may not always be perceived as immediately “pleasing” by some listeners, it allows for an accurate representation of the recording’s inherent qualities.

2. Exceptional Resolution: One of the standout features of the LS1be is its exceptional resolution across the entire frequency spectrum. It excels at revealing minute details and nuances within recordings. Whether it’s the woody texture of a cello, the delicate nuances of a freshly played violin string, or the subtleties in vocal performances, the LS1be offers a level of detail retrieval that is truly impressive. This level of resolution contributes to the overall transparency and realism of the sound.

3. Dynamic Capability: Despite its reputation as a neutral and precise speaker, the LS1be is no slouch when it comes to dynamics. It handles transients and impulses with immediacy and energy. Whether you’re listening to orchestral crescendos, the powerful beats of electronic music, or the impact of rock and metal, the LS1be is capable of delivering a dynamic and engaging performance. Its ability to convey the force and intensity of music is a testament to its studio-grade origins.

4. Spatial Presentation: The LS1be’s spatial presentation is notable for its openness and engagement. While it maintains accuracy and precision in soundstage positioning, it also leans slightly forward, creating a sense of presence and intimacy. This quality is particularly appealing for listeners who enjoy feeling closer to the music, as it invites them into the performance. The LS1be excels in creating a wide and enveloping soundstage that extends beyond the physical boundaries of the speakers, contributing to a captivating listening experience.

5. Versatility: One of the strengths of the LS1be is its versatility across different musical genres. It is not limited to a specific type of music but adapts well to various styles. Whether you’re indulging in the subtleties of classical chamber music, the intricate textures of electronic soundscapes, the raw power of rock, or the rhythmic complexity of jazz, the LS1be handles each genre with finesse and authenticity. Its neutrality allows it to faithfully reproduce the characteristics of each recording, ensuring that the essence of the music remains intact.

In conclusion, the Grimm LS1be plus SB1 subwoofer system is a remarkable speaker setup that combines studio-grade precision with a captivating and engaging listening experience. Its commitment to tonal neutrality, exceptional resolution, dynamic capability, spatial presentation, and versatility make it a compelling choice for audiophiles seeking a pure and unadulterated representation of music. While its design may not cater to every aesthetic preference, its sonic performance is sure to impress those who value accuracy and transparency in their audio playback.

Spatial Presentation

The LS1be’s spatial representation is noteworthy. It provides an engaging, lively, and open soundstage that draws listeners into the music. Unlike some speakers that remain true to the original recording’s stage, the LS1be leans slightly forward, offering a more inviting and organic listening experience. This characteristic can be preferred for its ability to create a more immersive and captivating musical experience.


The Grimm LS1be plus SB1 subwoofer speaker system is a high-quality, neutral, and transparent audio solution with roots in professional studio applications. Its exceptional resolution, clarity, and dynamic capabilities make it well-suited for a wide range of musical genres and room sizes. While the LS1be may present bass in a more precise and controlled manner compared to some competitors, its overall performance, coupled with its unique design philosophy, sets it apart in the world of high-end audio. Grimm Audio’s dedication to providing a pure and immersive listening experience makes the LS1be a compelling choice for audiophiles seeking unadulterated sound quality.

Profile Grimm LS1be + SB1:

  • Neutral across the entire frequency band (unless you set something else).
  • Can’t fill very large rooms with as much bass volume as you want so that you can get more bang for your buck with other speakers. The bass level is at normal levels or is tight and neutral in normal rooms.
  • The depth and definition in the bass are first-class – even at very high levels, the reproduction is completely dry and controlled, and nothing is ever slurred. Even more astonishing, This contouring is also achieved at very low levels; nothing blurs in the slightest, and it can be listened to deeply, even though it is so quiet. It’s a rare quality.
  • The mids and highs are kept linear and have a very high resolution. At best, in the upper octaves, you get a little more fine detail and timbre differentiation here and there in this class, but that is more in the homeopathic range. The great clarity of the Grimm makes voices, in particular, seem authentic.
  • Excellent fine dynamics and impulse reproduction. Coarse dynamic attacks are also carried out seamlessly. But there are speakers that offer more bass power.
  • Pleasantly involving stage that opens slightly towards the front with a nice wide panorama. The depth grading is good, even if it doesn’t immediately set the standard. The great thing about the Grimm’s spatial representation is that it seems completely free, that the music is completely detached from the speakers, and although (or precisely because?) the localization sharpness “technically” could be even higher, there is a very strong presence of the musicians in the room. Very good!
  • Professional processing. The handling of the input and level selection seems almost amusingly quirky to hi-fi users, as is often the case with products from the studio sector.


  • Model: Grimm LS1be + SB1
  • Concept: active, closed three-way speaker
  • Price: around 38,000 euros (pair)
  • Dimensions & Weight: 52 x 115 x 34 cm (WxHxD; Depth of stand/subwoofer, speaker: 16 cm; LS1be: 54 kg/piece, SB1: 11 kg/piece
  • Power: 2 x 1060 watts (LS1be: 2 x 180 watts/piece, SB1: 700 watts/piece)
  • Finishes: White, Caramel Bamboo, Natural Bamboo; Stand, base plate and subwoofer black
  • Interfaces: 1 x AES/EBU, 1 x analog in (XLR), control in and out, subwoofer link, USB to AES/EBU cable is included in delivery
  • Other: Software-supported setting options, including EQ in the bass and treble range
  • Warranty: 5 years