The tremendously powerful Grotto 15 can blend into virtually any environment without overwhelming the aesthetic design of the room. However, once the first bass note drops, the audience can easily sense its raw potential. The three full-faced grilles conceal the startling intensity of Grotto 15, making it an ideal choice for those looking for commanding bass in a more subtle package.
Utilizing state-of-the-art Klippel analysis, all Grotto Series drivers are specifically engineered for dynamic output with low distortion. Grotto 15 pairs dual 15-inch passive radiators with a matching 12-inch active woofer. This driver layout delivers the best of both worlds; the increased low frequency extension of a ported design and the more compact sizing and tighter bass attributed to sealed designs. All of the woofer cones are made from aluminum to ensure quick response, high output, and solid reliability. Aluminum is an ideal material for such an application, due to its excellent heat dissipation and high strength to weight ratio. Grotto Series subwoofers also feature rigid cast aluminum baskets and large motor structures to best handle the colossal power of the MT-2kW amplifier. While these drivers do not receive direct power, engineering the passives to the same standard as the active driver ensures they match both acoustically and aesthetically.
MartinLogan’s proprietary Magnitude Amplifiers unleash the full potential of the custom engineered Grotto woofers. The highly advanced Magnitude MT-2kW delivers up to 2,000w Peak(1,000w RMS) of low-distortion power for concussive impact and effortless musicality. This ultra-efficient Class-D amplifier delivers nearly endless reserves of clean power with incredible precision and control, even during the most demanding content.
Grotto subwoofers utilize the cutting edge, ultra-high resolution Vojtko DSP engine, named after MartinLogan’s Chief Audio Technologist, Joe Vojtko. Featuring a best-in-class 500MHz DSP with 64-bit processing, the Vojtko DSP engine controls all aspects of subwoofer performance in real time. This level of computing power enables advanced features like wireless app control, integrated wireless signal connection, and other advanced DSP functions with complete audible transparency, enabling MartinLogan engineers to calibrate the subwoofer for maximum output and fidelity. This sophisticated DSP engine enables compatibility with the award-winning Anthem Room Correction system.
This highly advanced software measures the in-room performance of the subwoofer and conducts custom equalization, tuning, and calibration to achieve the highest levels of bass impact, smoothness, and accuracy. Calibration only takes a few minutes using the ARC Genesis software, and an ARC Calibration Kit(sold separately) which works on both PC and Mac.
The cabinet plays a critical role in the sound quality of a speaker. Grotto 15 cabinets are made of one-inch thick MDF(Medium Density Fiberboard) with additional reinforcement on the woofer baffles and dual center braces, robust enough to withstand the forces of the 15-inch Hybrid Woofer System. This solid construction also provides a more stable platform for the woofer system, resulting in cleaner, more articulate bass.
Solid bass performance is a critical component of any audio system, and helps provide visceral impact to music and film soundtracks. Grotto subwoofers feature integrated anti-vibration feet to improve bass performance by reducing floor and wall vibrations. Drastically 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, the integrated anti-vibration feet can also aid in minimizing noise complaints by reducing vibration transfer into adjoining rooms. These feet are safe for all flooring types and the optional carpet spikes are included to further improve performance on carpeted floors.
Grotto subwoofers feature an array of wired installation options in addition to the convenience of the included wireless option. For the best connection, XLR is available for the LFE input. Both Stereo left/right and LFE input are available via RCA, and an RCA Sub Output is available to make it easier to chain multiple subs together, if needed. Grotto Subwoofers also feature speaker level inputs via banana plugs, which some enthusiasts prefer so the subwoofer is driven by the exact same signal being fed to the speakers, in essence receiving the sonic signature of the chosen amplifier. This also makes Grotto subwoofers compatible with nearly any setup, including balanced amplifiers. Although rare, as with all MartinLogan subwoofers, the available inputs can be used simultaneously if desired. The pristine processing and filtering made possible by the advanced Vojtko DSP engine enables Grotto subwoofers to offer the highest levels of input purity, regardless of the connection method. With a variety of input options to choose from, Grotto subwoofers can add superior bass reinforcement to nearly any system.
While a hard-wired connection is still the best method, for flexible placement options, Grotto subwoofers come with a built-in Wireless Receiver and Wireless Transmitter. Featuring lossless transmission, forward error correction, and low latency, even the most discerning enthusiast will be thrilled with the results.
MartinLogan’s Subwoofer Control app for iOS and Android devices offers the most personalized and convenient way to adjust a subwoofer. This allows the user to easily adjust settings such as Volume, DSP Mode, Phase, and other features providing the most intuitive control and ease of use. The Control App is also an invaluable tuning aid, enabling the user to hear the effects of setting changes from the listening position in real time.
To run Anthem Room Correction (ARC) with your speakers you will need to purchase a PBK or ARC Kit:
ARC Calibration Microphone Kit
(Please note that MartinLogan Perfect Bass Kit (PBK) microphones are fully compatible with Anthem Room Correction for MartinLogan speakers).
To download the most up-to-date version of ARC, please click the link below to go directly to Anthem's website.
ARC Genesis requires an ARC or PBK Microphone, a Mac OS X (10.12+) or Windows (7/8/8.1/10/11) computer, and an ARC or PBK compatible audio product. One USB port is required. If you are using a laptop computer, check power settings and battery meter before starting to ensure the procedure is not interrupted.
