MartinLogan Grotto 15 Subwoofer

The original Grotto subwoofer set a standard for clean, powerful bass in a compact, décor-friendly design. The all-new Grotto Series carries on that legacy with advanced amplification, precision drivers, and ARC Genesis Room Correction; delivering deep, controlled, and impactful bass from an elegantly understated form. Featuring MartinLogan’s largest, most powerful Hybrid Woofer System to date, Grotto 15 uses dual 15-inch passive radiators to enhance the low frequency output of its powerful, active 15-inch aluminum cone woofer. This high-output woofer system is driven by robust amplification and a best-in-class 64-bit DSP Engine to extract maximum performance. Grotto 15 offers a wide range of connectivity options including XLR, RCA, Speaker Level, and built-in wireless, plus the added convenience of the MartinLogan Subwoofer Control App. With support for the award-winning Anthem Room Correction(ARC) system, Grotto 15 can also be expertly tuned in a matter of minutes using the optional ARC Calibration Kit.  

Digital Signal Processor	Ultra High-Resolution 500MHz Vojtko DSP Engine with 64bit processing
Frequency Response	20–120 Hz ±3 dB (Anechoic via LFE input)
Low Frequency Transducer	Triple 15" (25.4cm) Hybrid Woofer System consisting of 1x high-excursion, aluminum cone in a cast aluminum basket with 2x aluminum cone passive radiators for enhanced low frequency output.
Cabinet	Sealed 1" thick MDF cabinet with dual center braces and reinforced MDF woofer baffles
Amplifier	MartinLogan Magnitude MT-2kW Amplifier: 2000W peak (1000W continuous)
Controls (Backplate)	Level: Interactive LED Backlit Knob, Min-Max Tone Sweep: Sweep Start and Pause (with status light) Power Mode: On, 12v Trigger, Auto Wireless Audio Pairing Button (for included MartinLogan wireless transmitter)
Controls (via Bluetooth)	Level: -40 to 12dB (Min-Max) Low-Pass Filter (Frequency): 35–120Hz (1° Increments) Low-Pass Filter (Order): Bypass, Third, Fourth Phase: 0–180° (1° Increments) Phase (Polarity): Normal, Inverted Preset Listening Modes: Movie, Music, Night 20–30Hz Level: ±10dB Anthem Room Correction (ARC Genesis): On, Off Tone Sweep (120-20Hz): On, Off, Pause (Frequency)
Inputs	Line Level: Left, Right, and LFE XLR: LFE Speaker Level: Left and Right (Requires Banana Plugs)
Finish	Gloss Black
Weight	118 lbs (53.5 kg)
Dimensions (HxWxD)	20.5" x 21.8" x 21.8" (52.2cm x 55.4cm x 55.4cm)