{"product_id":"grimm-audio-sb1-motion-feedback-subwoofer","title":"Grimm Audio SB1 Motion Feedback Subwoofer","description":"\u003cp\u003eThe Grimm Audio SB1 does what no conventional subwoofer can: it measures the cone's movement 96,000 times per second and corrects it in real time. Digital Motional Feedback reduces distortion by up to 30 dB, delivering bass that is linear to 20 Hz without the bloat, resonance, or delayed decay that plagues every other sub in this price range. Designed in the Netherlands to transform any \u003ca href=\"\/products\/grimm-audio-ls1a-loudspeaker\"\u003eGrimm LS1\u003c\/a\u003e speaker into a full three-way system, the SB1 sits beneath the loudspeaker between its support legs, connected by short cables that carry both signal and power.\u003c\/p\u003e\n\n\u003ch5\u003eKey Features of the Grimm Audio SB1\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDigital Motional Feedback (DMF):\u003c\/strong\u003e A piezoelectric acceleration sensor mounted directly on the cone feeds a 96 kHz correction loop, reducing distortion by up to 30 dB compared to conventional subwoofers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLinear to 20 Hz:\u003c\/strong\u003e Flat frequency response from 20 Hz to 250 Hz (+\/-2 dB) in half-space placement, with driver resonance tuned to 15 Hz (Q of 0.5).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e700W nCore Hypex Amplification:\u003c\/strong\u003e Class D power module delivers clean, controlled output with a maximum SPL of 96 dB per unit (102 dB per pair) across 30-250 Hz.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePhase-Corrected Crossover:\u003c\/strong\u003e When paired with any LS1 speaker, the system's DSP implements a phase-corrected crossover at 70 Hz without phase discontinuity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUpward-Firing 10\" Aluminum Woofer:\u003c\/strong\u003e Modified driver with acceleration sensor fires upward, transferring minimal energy into the LS1's support legs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSealed Enclosure:\u003c\/strong\u003e No port, no passive radiator. Multi-layered CNC-machined MDF construction eliminates cabinet resonance.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIEC Pass-Through:\u003c\/strong\u003e Built-in mains outlet powers the LS1 speaker directly, reducing cable clutter to a single power cord from the wall.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThird-Party Compatibility:\u003c\/strong\u003e A rear-panel switch enables standalone operation with non-Grimm speakers via XLR input.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUltra-Low DSP Latency:\u003c\/strong\u003e 38 microsecond processing delay ensures perfect time alignment with the main speakers.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch5\u003eDigital Motional Feedback: Engineering That Hears the Driver\u003c\/h5\u003e\n\u003cp\u003eBelow 100 Hz, loudspeaker drivers must move enormous volumes of air. High excursion levels and the fundamental driver resonance produce rising distortion and a characteristic \"thickening\" of bass that colors everything. Motional feedback, the concept of monitoring a driver's actual movement and correcting it electronically, has existed since the 1970s. Grimm Audio's implementation is different in both precision and execution.\u003c\/p\u003e\n\u003cp\u003eAn analog piezoelectric acceleration sensor is bonded to the SB1's aluminum cone, providing 16-bit resolution at 96 dB signal-to-noise ratio with bandwidth exceeding 3 kHz. This sensor feeds a digital correction loop that combines smart DSP processing with current-drive amplification. The result: up to 30 dB of distortion reduction across the effective feedback range (up to 250 Hz). The low-distortion aluminum woofer, already a high-performance driver, becomes something closer to a laboratory instrument. Bass notes start and stop with precision that sealed and ported designs simply cannot match. The technology is licensed from RMS Acoustics and refined by Grimm's own engineering team, building on a lineage that began with the LS1s-DMF in 2016.\u003c\/p\u003e\n\n\u003ch5\u003eBuilt for the Grimm LS1 System\u003c\/h5\u003e\n\u003cp\u003eThe SB1 was designed as the bass extension for Grimm's LS1 loudspeaker series, converting any two-way LS1 into a full three-way active system. Physically, the sub fits beneath the LS1 between its support legs, keeping the main speaker at the correct listening height while adding genuine deep bass capability. Short cables pass both digital data and power between the units, and the IEC pass-through means only one power cord runs to the wall per channel.\u003c\/p\u003e\n\u003cp\u003eThe LS1's internal DSP handles crossover duties, implementing a phase-corrected filter at 70 Hz that maintains the system's legendary time-domain accuracy. There is no external processor to configure, no crossover knob to adjust. The system simply works as an integrated whole. Reviewers consistently note that the SB1 \"disappears\" into the sound, filling out the bottom octaves without ever calling attention to itself.\u003c\/p\u003e\n\u003cp\u003eThe SB1 is compatible with all current LS1 models: the \u003ca href=\"\/products\/grimm-audio-ls1c-loudspeaker\"\u003eLS1c\u003c\/a\u003e, \u003ca href=\"\/products\/grimm-audio-ls1v2-loudspeaker\"\u003eLS1v2\u003c\/a\u003e, and \u003ca href=\"\/products\/grimm-audio-ls1a-loudspeaker\"\u003eLS1a\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch5\u003eThird-Party Speaker Compatibility\u003c\/h5\u003e\n\u003cp\u003eA rear-panel switch sets the SB1 to standalone mode for use with non-Grimm speakers. In this configuration, the sub accepts a mono XLR signal (RCA adapter compatible) and operates as a conventional powered subwoofer. Note that standalone mode does not include built-in volume control, adjustable crossover, or low-pass filtering. An external active crossover or AV receiver\/processor is required for proper integration with third-party systems. The Mono variant is sold as a single unit for this purpose.\u003c\/p\u003e\n\u003cp style=\"text-align: center; margin: 20px 0;\"\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/grimm_sb1_inline_rear_panel.jpg?v=1774033787\" alt=\"Grimm Audio SB1 rear panel showing LS1\/Other switch and XLR input\" style=\"display: block; margin-left: auto; margin-right: auto; max-width: 100%;\" loading=\"lazy\"\u003e\u003c\/p\u003e\n\n\u003ch5\u003eExplore the Full Grimm Audio Loudspeaker Series\u003c\/h5\u003e\n\u003cp\u003eThe SB1 pairs with every speaker in the Grimm LS1 range. The \u003ca href=\"\/products\/grimm-audio-ls1c-loudspeaker\"\u003eGrimm Audio LS1c\u003c\/a\u003e is the flagship two-way, featuring beryllium dome tweeter and the most refined cabinet construction. The \u003ca href=\"\/products\/grimm-audio-ls1v2-loudspeaker\"\u003eLS1v2\u003c\/a\u003e delivers the core LS1 experience at a lower price point, while the \u003ca href=\"\/products\/grimm-audio-ls1a-loudspeaker\"\u003eLS1a\u003c\/a\u003e makes the LS1 philosophy accessible to a wider audience. For source components, the \u003ca href=\"\/products\/grimm-audio-mu1-music-streamer\"\u003eMU1 Music Streamer\u003c\/a\u003e and \u003ca href=\"\/products\/grimm-audio-mu2-digital-music-streamer-dac-preamp\"\u003eMU2 Digital Music Streamer\u003c\/a\u003e were designed as the ideal digital front end for the LS1 system.\u003c\/p\u003e\n\n\u003ch5\u003eThe Listening Room Difference\u003c\/h5\u003e\n\u003cp\u003eWe're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on exceptional service and relentless passion for hifi. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.\u003c\/p\u003e\n\n\u003ch5\u003eGrimm Audio SB1 Specifications\u003c\/h5\u003e\n\u003ctable style=\"border-collapse: collapse; width: 100%;\"\u003e\n\u003cthead\u003e\n\u003ctr style=\"background-color: #f3f3f3;\"\u003e\n\u003cth style=\"padding: 12px; border: 1px solid #ddd; text-align: left; width: 34%;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"padding: 12px; border: 1px solid #ddd; text-align: left; width: 66%;\"\u003eDetails\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eType\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eActive sealed subwoofer with Digital Motional Feedback\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDriver\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e10\" modified aluminum woofer with piezoelectric acceleration sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eAmplification\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e700W nCore Hypex Class D\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e20-250 Hz +\/-2 dB (half space)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDriver Resonance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e15 Hz, Q = 0.5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eMaximum SPL (30-250 Hz, 1m)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e96 dB (single) \/ 102 dB (pair)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eMaximum Output at 20 Hz\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e89 dB (single) \/ 95 dB (pair)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eCrossover\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003ePhase-corrected at 70 Hz (with LS1 system)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDSP Latency\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e38 microseconds\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDistortion Reduction\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eUp to 30 dB via DMF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eEnclosure\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eSealed, multi-layered CNC-machined MDF\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eInput\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eXLR mono (RCA adapter compatible)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003ePower\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e90-240V, 50-60 Hz, 500W (IEC with pass-through for LS1)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eControls\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eLS1\/Other switch (rear panel)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eDimensions (W x D x H)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e358 x 340 x 213 mm (14.1 x 13.4 x 8.4 in)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eWeight\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e15 kg (33 lbs) per unit\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eFinish\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eBlack\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003e\u003cstrong\u003eCountry of Origin\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"padding: 12px; border: 1px solid #ddd;\"\u003eNetherlands\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Grimm Audio","offers":[{"title":"Stereo Set","offer_id":42655363792992,"sku":"GRISB1SET","price":14590.0,"currency_code":"USD","in_stock":true},{"title":"Mono - 3rd Party","offer_id":42655364055136,"sku":"GRISB1MONO","price":7295.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0555\/5073\/8528\/files\/01_grimm_sb1_front_no_grille.jpg?v=1774032690","url":"https:\/\/listenroom.com\/products\/grimm-audio-sb1-motion-feedback-subwoofer","provider":"The Listening Room","version":"1.0","type":"link"}