In the neverending race for the bottom octaves, MartinLogan is back with serious bass firepower. The audio pioneer has unveiled its all-new Grotto 12 and Grotto 15 subwoofers, featuring the company’s largest and most powerful Hybrid Woofer Systems to date. Following the August 2024 launches of the Dynamo Foundation, Dynamo, and Abyss Series, the Grotto 12 and 15 deliver extreme output and refinement for larger rooms.
“Subwoofers have been a key category for us at MartinLogan for over 20 years. As the latest addition to our new subwoofer lineup, we couldn’t be more happy for the Grotto namesake to return with such fanfare,” said Allan Tarrant, Senior Vice President of MartinLogan. “After the release of our new Dynamo Foundation, Dynamo, and Abyss models, people kept asking us about larger, even more powerful subwoofers. Consider the veil of secrecy lifted!”
MartinLogan Subwoofer Evolution: From Descent to Grotto Series
MartinLogan built its reputation on electrostatic loudspeakers, and for good reason: these panels are state-of-the-art when it comes to openness, transparency, and speed. Detail and air? Unmatched. But when it comes to chest-thumping impact, the panels just don’t move enough air. Since the Monolith electrostatics debuted in 1983, dealers have been hearing the same question: “What do I pair with these things to get real low end?” By 2001, MartinLogan finally had an answer with the Descent series subwoofers.
From there, they’ve been steadily sharpening their low-frequency game—adding depth, texture, and features with every generation. The most recent update came last year with the aforementioned three new subwoofer lines.
MartinLogan’s Abyss Series delivers compact, high-output bass with its Hybrid Woofer System—an active aluminum woofer paired with two passive radiators for tight, powerful performance. The Abyss 8 ($1,399.99 USD) uses a 500W RMS / 1,000W peak Magnitude MT-1kW amp, while the Abyss 10 ($1,899.99 USD) steps up to 800W RMS / 1,600W peak with the MT-1.6kW amplifier.
The new Grotto 12 and 15 subwoofers sit above the Abyss models in MartinLogan’s lineup, offering larger hybrid woofers and up to 2kW peak power for even more output and room-pressurizing bass, making them the go-to choice for bigger spaces or listeners seeking maximum impact.
The middle tier is the Dynamo Series, available in 8-, 10-, and 12-inch sizes. Like the Abyss, it packs modern conveniences—wireless capability, room correction, and an app that doesn’t look like it was coded in 1997.
At the entry level, the Dynamo Foundation Series offers the same drivers but orients them down-firing, ditches the wireless frills, and keeps things wired-only to hit a more approachable price—without turning into boom-box territory.
MartinLogan Grotto 12 & 15 Subwoofers: Triple Hybrid Woofers with 2kW Magnitude Amplification
The Grotto models are the new MartinLogan flagship subwoofers, offering high-output, room-pressurizing performance at a more approachable price point. The Grotto 12 comes in at $2,299.99 USD, while the larger Grotto 15 pushes up to $2,799.99 USD.
“The original Grotto was the first MartinLogan product that I ever owned, and it remains in use to this day. I am thrilled to have been a part of bringing out its successors,” said Andrew Lindsey, Product Manager at MartinLogan. “The new Grotto 12 and Grotto 15 more than carry on the legacy of the original, delivering massive output capability and incredible refinement—all in a subtle, stylish design that can pressurize even larger rooms.”
Key Features and Benefits of the Grotto Series
The MartinLogan Grotto 12 and 15 aren’t here to play nice—they’re built to move serious air. Both models use a Hybrid Woofer System, pairing an active aluminum woofer with dual passive aluminum radiators. The result? The punch and output of a ported subwoofer, but with the tight, controlled bass you’d expect from a sealed design.
Under the hood, the Magnitude MT-2kW amplifier pushes up to 2,000W peak (1,000W RMS), giving these subs enough headroom to crush the biggest rooms without sounding strained. Every nuance of your music is preserved thanks to a 500MHz, 64-bit DSP engine that handles all the advanced processing.
The cabinets are built like tanks—1-inch MDF with reinforced baffles and center braces—so your bass hits hard without cabinet flex or coloration. Anti-vibration feet keep your neighbors (and your floorboards) from complaining, while integrated wireless connectivity makes for a clean setup with near-zero latency.
Installation and control are a breeze. RCA, XLR, speaker-level inputs, and sub out connections give you maximum flexibility, and the MartinLogan Subwoofer Control App lets you tweak settings from your seat. Grotto subs also support Anthem Room Correction (ARC), so you can dial in room-specific EQ and get the most out of your walls—and your patience.
Grotto 12 Specifications
- Application: Subwoofer
- Frequency Response: 22–120 Hz ±3 dB (Anechoic via LFE input)
- Low-Frequency Transducer: Triple 12″ Hybrid Woofer System (1x high-excursion aluminum active woofer + 2x aluminum passive radiators)
- Amplifier: Magnitude MT-2kW Class-D; 1,000W RMS / 2,000W Peak
- Digital Signal Processing: 500MHz Vojtko DSP Engine with 64-bit processing
- Cabinet: Sealed 1″ MDF with center brace and reinforced woofer baffles
- Controls (Backplate): Level (Interactive LED knob), Tone Sweep, Power Mode (On, 12v Trigger, Auto), Wireless Pairing
- Controls (App/Bluetooth): Level (-40 to +12dB), Low-Pass Filter (35–120 Hz, 1° increments), Phase (0–180°, Polarity normal/inverted), Preset Listening Modes (Movie, Music, Night), Tone Sweep (20–120 Hz), Anthem Room Correction On/Off
- Inputs: RCA Left/Right, LFE XLR, Speaker Level Left/Right
- Outputs: RCA Sub Out
- Wireless: Integrated Receiver; Transmitter Included
- Power Draw: Max 1,000W; Standby Wireless Enabled <2W; Standby Wireless Disabled 0.5W
- Feet: Integrated Anti-Vibration Feet (carpet spikes included)
- Weight: 82.5 lbs (37.4 kg)
- Dimensions (HxWxD): 17.8″ x 17.9″ x 17.9″ (45.2 x 45.4 x 45.4 cm)
- Finish: Gloss Black
Grotto 15 Specifications
- Application: Subwoofer
- Frequency Response: 20–120 Hz ±3 dB (Anechoic via LFE input)
- Low-Frequency Transducer: Triple 15″ Hybrid Woofer System (1x high-excursion aluminum active woofer + 2x aluminum passive radiators)
- Amplifier: Magnitude MT-2kW Class-D; 1,000W RMS / 2,000W Peak
- Digital Signal Processing: 500MHz Vojtko DSP Engine with 64-bit processing
- Cabinet: Sealed 1″ MDF with dual center braces and reinforced woofer baffles
- Controls (Backplate): Level (Interactive LED knob), Tone Sweep, Power Mode (On, 12v Trigger, Auto), Wireless Pairing
- Controls (App/Bluetooth): Level (-40 to +12dB), Low-Pass Filter (35–120 Hz, 1° increments), Phase (0–180°, Polarity normal/inverted), Preset Listening Modes (Movie, Music, Night), Tone Sweep (20–120 Hz), Anthem Room Correction On/Off
- Inputs: RCA Left/Right, LFE XLR, Speaker Level Left/Right
- Outputs: RCA Sub Out
- Wireless: Integrated Receiver; Transmitter Included
- Power Draw: Max 1,000W; Standby Wireless Enabled <2W; Standby Wireless Disabled 0.5W
- Feet: Integrated Anti-Vibration Feet (carpet spikes included)
- Weight: 118 lbs (53.5 kg)
- Dimensions (HxWxD): 20.5″ x 21.8″ x 21.8″ (52.2 x 55.4 x 55.4 cm)
- Finish: Gloss Black
The Bottom Line
MartinLogan’s Grotto 12 and 15 subwoofers redefine bass performance with their advanced Hybrid Woofer Systems, integrating high-excursion aluminum woofers with dual aluminum passive radiators. This design delivers the output of a ported subwoofer with the tight bass of a sealed enclosure.
Powered by the Magnitude MT-2kW amplifier, these models provide up to 2000W peak power, ensuring deep, distortion-free bass. The 500MHz Vojtko DSP engine offers precise tuning and integration with the Anthem Room Correction system, while the reinforced MDF cabinets and anti-vibration feet enhance performance and reduce unwanted resonance.
However, the subwoofer market is increasingly competitive. The SVS SB-5000 R|Evolution stands out with its formidable 15-inch driver and dual monoblock amplifier delivering 5000W peak power, complemented by a 295MHz DSP for precise control.
Additionally, REL’s Serie S lineup introduces faster, lighter drivers and amplifiers derived from their Reference models, aiming to provide more nuanced and better-integrated bass. DALI’s SUB V-16 F boasts a 16-inch driver and 1500W RMS amplification, designed for deep bass extension and precision. Meanwhile, Raidho’s TD8 and TD10 subwoofers feature diamond-coated drivers and ultra-low-latency amplification, targeting high-end audiophile markets.
In this competitive landscape, the Grotto 12 and 15 subwoofers distinguish themselves with their unique combination of power, precision, and innovative design, offering audiophiles a compelling choice for elevating their audio experience.
For more information: martinlogan.com
Where to buy:
- Grotto 12: Gloss Black
- $2,299.99 USD | $2,599.99 CAD
- Grotto 15: Gloss Black
- $2,799.99 USD | $3,199.99 CAD
Related Reading:
- REL Serie S 2025 Subwoofers Bring State-Of-The-Art Bass Honoring 35 Years Of Subwoofer Innovation
- MartinLogan Dynamo 10 Subwoofer Review: Quick Enough For Ribbon Speakers?
- Velodyne Acoustics And Playback Distribution Debut New U.S. Distribution Partnership And SPL-X Series Subwoofers At CEDIA 2025
- SVS 5000 R|Evolution Subwoofers Let You Feel Movie Night In The Next Zip Code
