• Digital motional feedback for 30 dB less distortion
• Linear response down to 20 Hz
• Turns the LS1 into a powerful 3-way system
• DSP controlled frequency curve
• Phase corrected crossover at 70 Hz in LS1
• Modified woofer and 700W class D amplifier
• Mains outlet for LS1 minimizes cable clutter
• Switch for use without LS1

The SB1 with ‘DMF’ is a technological marvel. By applying ‘Digital Motional Feedback’, a control technology from the renowned Dutch high-tech industry, it became possible to achieve exceptionally low levels of distortion and full dynamic control. With an SB1 added for the bass frequencies, the LS1 system offers low distortion over the full audio band and redefines the term ‘transparency’. This is bass control like you’ve never experienced before.

“Digital Motional Feedback offers bass control like you’ve never experienced before.”

At frequencies below 100 Hz loudspeaker drivers need to move a vast amount of air and therefore have high excursion levels, while also the fundamental resonance – which is present in any loudspeaker – induces unwanted delayed effects. The result is that all conventional loudspeakers exhibit a rising distortion in the bass region with additional “thickening” of the bass by the resonance.

In electronics, feedback is used to minimise distortion. To apply feedback in electro-mechanical systems like an active loudspeaker, an acceleration sensor needs to be mounted on the cone to monitor its motions. This so called “Motional Feedback” technology has been presented a few times before in history but the precision and control as found in the Grimm Audio SB1 is unique. By adding smart digital processing and current drive, the low distortion of the already high-performance aluminium woofer is further reduced by as much as 30 dB, solving all problems that are related to low frequency resonances and distortion.

The SB1 sub is a perfect partner for the LS1v2 and an excellent match for the LS1be. It is even a smart extension for the LS1a. A switch facilitates use of the SB1 with third party systems, so the virtues of Digital Motional Feedback can be enjoyed by many.