Grimm Audio introduce to you the successor of our eminent LS1s-DMF motional feedback subwoofer: the SB1. It takes our “Digital Motional Feedback” (DMF) technology to the next level. “Upon its introduction in 2017 we pioneered true high tech audio mechatronics in the LS1s-DMF. Philips’ motional feedback concept of the 70’s was improved with a ground breaking factor 10 using modern sensors and DSP technology. The past years taught us a lot about this exciting technology. With that experience we were able to improve both the performance and manufacturability of our subwoofer, which led to the SB1. “

Most noticable on the outside of the new SB1 is that we selected a different (black) driver which offers even lower distortion. Under the hood there are many more changes, from a new sensor that’s mounted on the driver in a novel way, to completely redesigned DMF electronics and power supplies. The result is ‘more of the same’: the low distortion is even lower and the well controlled resonances are even more controllled.

Interesting to many is the addition of a switch that makes the SB1 suitable for use without LS1s. The SB1 is the smallest subwoofer on the market with a powerful linear response from 20 Hz to 500 Hz. Any system with active crossover capabilities can now take advantage of this.

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.

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 Seas woofer is further reduced by as much as 30 dB, solving all problems that are related to low frequency resonances and distortion.

SB1 Features

  • 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