{"product_id":"martinlogan-grotto-15-subwoofer","title":"MartinLogan Grotto 15 Subwoofer","description":"\u003ch1\u003eGrotto 15 Subwoofer\u003c\/h1\u003e\n\u003cp\u003eGrotto 15 continues the legacy of the original Grotto: serious, clean bass from a cabinet that blends discreetly into the room. It uses MartinLogan's largest and most powerful Hybrid Woofer System to date, pairing an active 15-inch aluminium-cone woofer with dual 15-inch passive radiators, driven by a 2,000W peak (1,000W RMS) Magnitude MT-2kW amplifier and a 64-bit Vojtko DSP engine. XLR, RCA, speaker-level and built-in wireless connections, app control and ARC Genesis room correction support make it as flexible as it is powerful.\u003c\/p\u003e\n\u003ch2\u003eBold Performance, Subtle Styling\u003c\/h2\u003e\n\u003cp\u003eThree full-face grilles keep Grotto 15 visually understated, but its commanding output becomes obvious the moment the first bass note lands. Ideal if you want authoritative low end without a subwoofer dominating the décor.\u003c\/p\u003e\n\u003ch2\u003e15\" Hybrid Woofer System\u003c\/h2\u003e\n\u003cp\u003eDeveloped with Klippel analysis for high output and low distortion, the active 15-inch woofer works with two matched 15-inch passive radiators. This gives the deep extension of a ported design with the tighter, more compact character of a sealed one. All cones are aluminium for fast response, high output and reliability, mounted in rigid cast-aluminium baskets with large motor structures.\u003c\/p\u003e\n\u003ch2\u003eMagnitude MT-2kW Amplifier\u003c\/h2\u003e\n\u003cp\u003eMartinLogan's proprietary Class-D Magnitude amplifier delivers up to 2,000W peak (1,000W RMS) of low-distortion power, with ample reserves for concussive impact and effortless musicality on even the most demanding content.\u003c\/p\u003e\n\u003ch2\u003eVojtko DSP and ARC Genesis\u003c\/h2\u003e\n\u003cp\u003eThe 500MHz, 64-bit Vojtko DSP engine controls performance in real time and enables Anthem Room Correction (ARC Genesis). Room calibration takes only minutes using the optional ARC Calibration Kit (sold separately).\u003c\/p\u003e\n\u003ch2\u003eSolid Construction and Anti-Vibration Feet\u003c\/h2\u003e\n\u003cp\u003eThe sealed 1-inch MDF cabinet has reinforced woofer baffles and dual centre braces for a stable platform and cleaner bass. Integrated anti-vibration feet reduce floor and wall vibration (carpet spikes included).\u003c\/p\u003e\n\u003ch2\u003eConnectivity and Control\u003c\/h2\u003e\n\u003cp\u003eXLR LFE, RCA stereo and LFE, speaker-level inputs and an RCA sub output. A wireless receiver is built in and a wireless transmitter is included. Adjust volume, crossover, phase and listening modes from your seat with the MartinLogan Subwoofer Control app.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003e\u003cem\u003eSpecifications are subject to change without notice.\u003c\/em\u003e\u003c\/p\u003e\n\u003cstyle\u003e\n#ml-grotto15-specs { width:100%; border-collapse:collapse; border:none; font-size:0.95em; }\n#ml-grotto15-specs td { padding:10px 14px; border:none; vertical-align:top; }\n#ml-grotto15-specs tr:nth-child(odd) td { background-color:#ffffff; }\n#ml-grotto15-specs tr:nth-child(even) td { background-color:#d0d0d0; }\n#ml-grotto15-specs td:first-child { font-weight:600; width:35%; }\n\u003c\/style\u003e\n\u003ctable id=\"ml-grotto15-specs\"\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency Response\u003c\/td\u003e\n\u003ctd\u003e20–120 Hz ±3 dB (anechoic, via LFE input)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLow Frequency Transducer\u003c\/td\u003e\n\u003ctd\u003eTriple 15\" Hybrid Woofer System: 1× high-excursion aluminium cone in a cast-aluminium basket, plus 2× aluminium cone passive radiators\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAmplifier\u003c\/td\u003e\n\u003ctd\u003eMartinLogan Magnitude MT-2kW: 2,000W peak (1,000W continuous)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDigital Signal Processing\u003c\/td\u003e\n\u003ctd\u003eUltra high-resolution 500MHz Vojtko DSP engine with 64-bit processing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCabinet\u003c\/td\u003e\n\u003ctd\u003eSealed 1\" MDF cabinet with dual centre braces and reinforced woofer baffles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs\u003c\/td\u003e\n\u003ctd\u003eLine level: Left, Right and LFE (RCA)\u003cbr\u003eXLR: LFE\u003cbr\u003eSpeaker level: Left and Right (requires banana plugs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutput\u003c\/td\u003e\n\u003ctd\u003eRCA Sub Out (combines and repeats all incoming signals)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWireless\u003c\/td\u003e\n\u003ctd\u003eIntegrated wireless receiver, wireless transmitter included\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControls (Backplate)\u003c\/td\u003e\n\u003ctd\u003eLevel: LED backlit knob\u003cbr\u003eTone Sweep: start\/pause with status light\u003cbr\u003ePower Mode: On, 12V Trigger, Auto\u003cbr\u003eWireless pairing button\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eControls (via Bluetooth app)\u003c\/td\u003e\n\u003ctd\u003eLevel: −40 to +12dB\u003cbr\u003eLow-Pass Filter: 35–120Hz (1Hz steps); Bypass, Third or Fourth order\u003cbr\u003ePhase: 0–180° (1° steps); Polarity: Normal, Inverted\u003cbr\u003eListening Modes: Movie, Music, Night\u003cbr\u003e20–30Hz Level: ±10dB\u003cbr\u003eARC Genesis: On\/Off\u003cbr\u003eTone Sweep (120–20Hz)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Draw\u003c\/td\u003e\n\u003ctd\u003eMax: 1000W\u003cbr\u003eStandby (wireless disabled): 0.5W\u003cbr\u003eStandby (wireless enabled): \u0026lt;2W (transmitter and subwoofer combined)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFeet\u003c\/td\u003e\n\u003ctd\u003eIntegrated anti-vibration feet (carpet spikes included)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions (H × W × D)\u003c\/td\u003e\n\u003ctd\u003e52.2 × 55.4 × 55.4 cm (20.5\" × 21.8\" × 21.8\")\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e53.5 kg (118 lbs)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish\u003c\/td\u003e\n\u003ctd\u003eGloss Black\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSold As\u003c\/td\u003e\n\u003ctd\u003eEach\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e","brand":"MartinLogan","offers":[{"title":"Gloss Black","offer_id":67826532974686,"sku":"GRO15","price":69990.0,"currency_code":"ZAR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/2577\/1494\/files\/grotto15-product-page-hero1.jpg?v=1792659706","url":"https:\/\/www.ultrasound.co.za\/products\/martinlogan-grotto-15-subwoofer","provider":"Ultra Sound \u0026 Vision","version":"1.0","type":"link"}