Grotto series subwoofers offer a unique combination of understated, minimalist styling and impressively powerful, yet articulate performance. Utilizing our largest, and most powerful Hybrid Woofer Systems to date, Grotto 12 and Grotto 15 pack an incredible feature list and massive power into a classy, room friendly design, making them an ideal choice for those looking for a high performance, high output subwoofer that won’t look out of place. The Hybrid Woofer System used in the Grotto series, pairs either a 12" or 15" active aluminum woofer with two equally sized, custom-designed aluminum passive radiators. This driver layout provides the massive surface area necessary to achieve the increased output and lower distortion of a ported design while maintaining the more compact sizing and tighter bass typically associated with a sealed design. Powering the Hybrid Woofer System is the brawn of MartinLogan’s powerful Magnitude® MT-2kW amplifier, capable of delivering up to 2000 watts of peak power (1000W RMS), and the brains of the Ultra High Resolution Vojtko DSP Engine, a best-in-class 500MHz DSP with 64bit processing. With their high output, low distortion Hybrid Woofer Systems paired with powerful and precise amplification and processing, Grotto series subwoofers have the ideal recipe for highly detailed and powerful bass performance even in larger rooms. Although correct placement plays a key role in optimizing subwoofer performance, getting a cable where you need it can be challenging. With the inconvenience of running long lengths of cable through walls, along baseboards or under floors and carpets, properly concealing the subwoofer cable is not always a simple task. To solve the problem, Grotto Series subwoofers incorporate a built-in Wireless Receiver for use with the included Wireless Subwoofer Transmitter. With quick and easy setup thanks to direct pairing, eliminating cable clutter has never been easier and with lossless transmission and low latency, even the most discerning enthusiast will be thrilled with the results. Solid bass performance is a critical component of any audio system, and helps provide visceral impact to your entertainment. Grotto subwoofers use integrated anti-vibration feet to improve bass performance while reducing floor and wall vibrations. By dramatically reducing the energy transfer between the subwoofer and the floor, unwanted room rattles and buzzes are removed, leaving tighter, cleaner bass and improved system clarity and dynamics. As a less intrusive alternative to acoustic room treatments, Grotto’s integrated anti-vibration feet can also aid in minimizing noise complaints by reducing vibration transfer into adjoining rooms. Out of the box, Grotto’s anti-vibration feet are safe for all flooring types, and optional carpet spikes are included to further improve performance on carpeted floors. Grotto subwoofers also take advantage of MartinLogan’s Subwoofer Control app for iOS and Android devices, allowing you to easily adjust settings like Volume, DSP Mode, Phase, and many others right from the comfort of your seat for ultimate control and ease of tuning. With 3 DSP modes for Movies, Music, or Night, you can optimize the performance of your subwoofer with a single press in the app. Choose Movie for the highest output, Music for lowest distortion, or Night to tame things down and help reduce noise complaints. With connections for both RCA and XLR LFE, Stereo RCA, and Speaker level, Grotto subwoofers are an ideal choice for both Home Theater and Music applications, integrating seamlessly into any system. The Subwoofer Out connection also makes it easy to add additional subwoofers to your system, further increasing bass performance. As with all MartinLogan subwoofers, Grotto models are designed to work with any speaker system while also being uniquely engineered to keep pace with the renowned clarity of MartinLogan loudspeakers. The high output, low distortion Hybrid Woofer System paired with the power and precision of MartinLogan’s Ultra High Resolution Vojtko DSP Engine, and Magnitude series amplifiers provides a recipe for highly detailed and powerful bass performance even in larger rooms.

• The MartinLogan Sound: MartinLogan subwoofers are uniquely engineered to keep pace with the exotic thin film technologies utilized in MartinLogan loudspeakers. With a focus on high performance and decor friendly design, MartinLogan subwoofers expertly blend audiophile musicality, theatrics, and precision with powerful output, all into a compact space.
• Grotto Heritage: The original Grotto™ subwoofer used trickle down technology from MartinLogan’s flagship subwoofers to deliver clean, powerful, and articulate bass in a decor friendly design. The all new Grotto series carries on that legacy and takes it to the next level. Its subtle appearance belies the raw performance concealed beneath its grilles.
• High-Performance Audio with Flexible, Elegant Design: MartinLogan’s Grotto Series subwoofers blend audiophile precision, dynamic output, and décor-friendly style. Engineered to complement MartinLogan’s advanced thin-film speakers, Grotto models integrate seamlessly into any system with versatile wired (XLR, RCA, Speaker Level) and low-latency wireless connections for effortless, flexible installation.
• Hybrid Woofer System: The Grotto 12 features a 12" aluminum active woofer paired with dual 12" passive radiators, combining the depth of a ported design with the control of a sealed sub. Precision-tuned using Klippel analysis, its lightweight, rigid aluminum drivers deliver fast response, low distortion, and exceptional clarity—ideal for achieving powerful, accurate bass in a compact form.
• Magnitude MT-2kW Amplifier: The Grotto 12’s Magnitude MT-2kW amplifier delivers up to 2000 W Peak (1000 W RMS) of ultra-clean Class-D power. Engineered for precision and control, it drives the 12-inch Hybrid Woofer System with deep impact and effortless musicality. Highly efficient and low-distortion, it provides massive dynamic headroom, ensuring tight, accurate bass performance even under the most demanding conditions.
• Ultra High Resolution Vojtko DSP Engine: The Grotto 12 features MartinLogan’s ultra-high-resolution Vojtko DSP engine, a 500 MHz, 64-bit processor managing every aspect of performance in real time. It enables app control, wireless connectivity, and advanced DSP functions with total transparency. Tuned for maximum output and fidelity, it also supports Anthem Room Correction for perfectly optimized bass in any space.
• Integrated Anti-Vibration Feet: The Grotto 12 features integrated anti-vibration feet that enhance bass clarity by reducing floor and wall vibrations. By limiting energy transfer, they eliminate unwanted rattles and resonance, resulting in tighter, more accurate bass. Safe for all flooring types, these feet also help reduce noise into adjoining rooms, with optional carpet spikes included for added stability and performance.
• MartinLogan Subwoofer Control App: By far the most convenient way to adjust a subwoofer, MartinLogan’s Subwoofer Control app for iOS and Android devices allows you to easily adjust settings like Volume, DSP Mode, Phase, and many others right from the comfort of your seat for ultimate control and ease of tuning.
• ARC Genesis Ready: Grotto subwoofers are compatible with the award winning Anthem Room Correction system. This highly advanced software measures subwoofer performance in your room and then performs custom equalization, tuning, and calibration to achieve the highest levels of bass impact, and accuracy possible in your specific installation. Requires an ARC Calibration Microphone and PC or Mac computer (sold separately).
• Built-In Wireless Connection: Although correct placement plays a key role in optimizing subwoofer performance, getting a cable where you need it can be challenging. To solve the problem, Grotto subwoofers incorporate a built-in Wireless Receiver for use with the included Wireless Subwoofer Transmitter. With quick and easy setup, eliminating cable clutter has never been easier and with lossless transmission and low latency, even the most discerning enthusiast will be thrilled with the results.
• Inputs: Grotto subwoofers advanced Magnitude amplifiers have a suite of connection options available. In addition to the built-in wireless option, Grotto subwoofers offer LFE RCA, Stereo RCA, LFE XLR, and Speaker Level Connections for maximum flexibility. Grotto subwoofers also have an RCA Output making it easy to add additional subwoofers to any system.
• The MartinLogan Sound: MartinLogan subwoofers are uniquely engineered to keep pace with the exotic thin film technologies utilized in MartinLogan loudspeakers. With a focus on high performance and decor friendly design, MartinLogan subwoofers expertly blend audiophile musicality, theatrics, and precision with powerful output, all into a compact space.
• Grotto Heritage: The original Grotto™ subwoofer used trickle down technology from MartinLogan’s flagship subwoofers to deliver clean, powerful, and articulate bass in a decor friendly design. The all new Grotto series carries on that legacy and takes it to the next level. Its subtle appearance belies the raw performance concealed beneath its grilles.
• High-Performance Audio with Flexible, Elegant Design: MartinLogan’s Grotto Series subwoofers blend audiophile precision, dynamic output, and décor-friendly style. Engineered to complement MartinLogan’s advanced thin-film speakers, Grotto models integrate seamlessly into any system with versatile wired (XLR, RCA, Speaker Level) and low-latency wireless connections for effortless, flexible installation.
• Hybrid Woofer System: The Grotto 12 features a 12" aluminum active woofer paired with dual 12" passive radiators, combining the depth of a ported design with the control of a sealed sub. Precision-tuned using Klippel analysis, its lightweight, rigid aluminum drivers deliver fast response, low distortion, and exceptional clarity—ideal for achieving powerful, accurate bass in a compact form.
• Magnitude MT-2kW Amplifier: The Grotto 12’s Magnitude MT-2kW amplifier delivers up to 2000 W Peak (1000 W RMS) of ultra-clean Class-D power. Engineered for precision and control, it drives the 12-inch Hybrid Woofer System with deep impact and effortless musicality. Highly efficient and low-distortion, it provides massive dynamic headroom, ensuring tight, accurate bass performance even under the most demanding conditions.
• Ultra High Resolution Vojtko DSP Engine: The Grotto 12 features MartinLogan’s ultra-high-resolution Vojtko DSP engine, a 500 MHz, 64-bit processor managing every aspect of performance in real time. It enables app control, wireless connectivity, and advanced DSP functions with total transparency. Tuned for maximum output and fidelity, it also supports Anthem Room Correction for perfectly optimized bass in any space.
• Integrated Anti-Vibration Feet: The Grotto 12 features integrated anti-vibration feet that enhance bass clarity by reducing floor and wall vibrations. By limiting energy transfer, they eliminate unwanted rattles and resonance, resulting in tighter, more accurate bass. Safe for all flooring types, these feet also help reduce noise into adjoining rooms, with optional carpet spikes included for added stability and performance.
• MartinLogan Subwoofer Control App: By far the most convenient way to adjust a subwoofer, MartinLogan’s Subwoofer Control app for iOS and Android devices allows you to easily adjust settings like Volume, DSP Mode, Phase, and many others right from the comfort of your seat for ultimate control and ease of tuning.
• ARC Genesis Ready: Grotto subwoofers are compatible with the award winning Anthem Room Correction system. This highly advanced software measures subwoofer performance in your room and then performs custom equalization, tuning, and calibration to achieve the highest levels of bass impact, and accuracy possible in your specific installation. Requires an ARC Calibration Microphone and PC or Mac computer (sold separately).
• Built-In Wireless Connection: Although correct placement plays a key role in optimizing subwoofer performance, getting a cable where you need it can be challenging. To solve the problem, Grotto subwoofers incorporate a built-in Wireless Receiver for use with the included Wireless Subwoofer Transmitter. With quick and easy setup, eliminating cable clutter has never been easier and with lossless transmission and low latency, even the most discerning enthusiast will be thrilled with the results.
• Inputs: Grotto subwoofers advanced Magnitude amplifiers have a suite of connection options available. In addition to the built-in wireless option, Grotto subwoofers offer LFE RCA, Stereo RCA, LFE XLR, and Speaker Level Connections for maximum flexibility. Grotto subwoofers also have an RCA Output making it easy to add additional subwoofers to any system.