The REL HT/1205 MKII is a powerful 12-inch home theater subwoofer featuring a 500-watt Class D amplifier and lightweight CarbonGlas™ driver for deep, high-impact bass. REL PerfectFilters™ analogue circuitry delivers controlled low-frequency extension into the 20 Hz range while an 8 Hz subsonic filter helps manage infrasonic soundtrack noise. Its upgraded driver, amplifier, and cabinet allow it to play approximately 50% louder than its predecessor while maintaining speed and precision for movies and music. Optional HT-Air™ 5.8 GHz wireless connectivity and compatibility with REL HT/3D™ systems make the HT/1205 MKII a flexible choice for premium home theater installations.
Get the Details

REL HT/1205 MKII

The REL HT/1205 MKII is a high-output 12-inch powered home theater subwoofer engineered to deliver the deep, dynamic bass demanded by modern movie soundtracks without sacrificing speed, precision, or musicality. Building on the original HT/1205, the MKII delivers up to 50% greater output while combining a redesigned CarbonGlas™ driver, a powerful 500-watt Class D amplifier, refined PerfectFilters™ analogue circuitry, and a compact, heavily braced cabinet designed specifically for high-performance home theater systems. Its lightweight glass-fibre cone and true carbon-fibre center cap are supported by larger magnets and an upgraded suspension system for tremendous output with fast, controlled performance. The redesigned amplifier incorporates thicker circuit boards, an upgraded power supply, and MOSFET modules rated at 800 watts, giving its 500-watt output substantial operating headroom. REL's second-generation PerfectFilters™ circuitry combines ultra-fast crossovers, elevation filters, integrated limiters, and an all-analogue subsonic filter beginning at 8 Hz to deliver controlled bass extending into the 20 Hz range. A lower, sleeker cabinet with solid bracing, a 12mm-thick vibration-damping top panel, five coats of hand-polished piano-black lacquer, and line-grained black composite bodywork gives the HT/1205 MKII a premium appearance to match its performance. Designed primarily for .1/LFE reproduction, it can supplement other REL subwoofers in high-output theater systems, integrate into REL HT/3D™ installations, and use optional HT-Air™ technology for uncompressed 5.8 GHz wireless transmission up to 60 feet. Despite its home theater focus, the HT/1205 MKII also provides the speed, weight, and articulation needed for compelling music reproduction.

What It's Good At:

• High-impact home theater bass: A 500-watt Class D amplifier and high-output CarbonGlas™ driver deliver the explosive dynamics needed for demanding movie soundtracks and .1/LFE effects.
• Deep, controlled low frequencies: REL's specially developed home theater filters produce exceptionally flat bass extending into the 20 Hz range, while an analogue subsonic filter beginning at 8 Hz controls unwanted infrasonic information.
• Greater output than the previous generation: The HT/1205 MKII is designed to play approximately 50% louder than its predecessor while improving precision, subtlety, and control.
• Fast, articulate driver performance: Glass-fibre and carbon-fibre construction combines low moving mass with high stiffness, while upgraded magnets and suspension components help the driver remain controlled at high output levels.
• Premium performance without an oversized enclosure: A compact, heavily braced cabinet uses proportions influenced by REL's Reference models and a vibration-damping 12mm polished top panel.
• Flexible theater integration: Dedicated .1/LFE performance, compatibility with REL HT/3D™ systems, and optional HT-Air™ 5.8 GHz wireless connectivity make the subwoofer adaptable to sophisticated theater installations.

REL HT/1205 MKII Full Specifications:

• Model: REL HT/1205 MKII
• Product Type: Powered home theater subwoofer
• Series: Serie HT
• Primary Application: Dedicated home theater and .1/LFE reproduction
• Secondary Application: Music reproduction
• Driver Type: CarbonGlas™ driver
• Driver Diameter: 12 inches
• Metric Driver Specification: 300 mm in the supplied introductory and performance information; one supplied driver section lists 350 mm and should be verified before publication
• Primary Cone Material: Glass fibre
• Center Cap Material: True carbon fibre
• Driver Design: Lightweight, stiff, quiet, pistonic construction
• Magnet System: Larger, more powerful magnets than the previous design
• Suspension: Upgraded suspension system designed for control at the limits of the amplifier and driver
• Amplifier Power: 500 watts
• Amplifier Type: Class D
• Amplifier Characteristic: Cool-running design
• MOSFET Power Module Rating: 800 watts
• Amplifier Construction: Thicker circuit boards
• Power Supply: Upgraded power supply design
• Amplifier Design Objective: High output, dynamic performance, and long-term durability
• Amplifier Development: Developed with a tier-one amplifier supplier
• Low-Frequency Performance: Exceptionally flat bass extending into the 20 Hz range
• Filter System: REL PerfectFilters™
• Filter Architecture: Analogue
• Crossover Design: Ultra-fast crossover filters
• Elevation Filters: Included to extend deep-bass flatness
• Limiters: Integrated limiters
• Secondary Filters: Refined second-generation design operating at higher frequencies
• Secondary Filter Purpose: Enhances the realism and rarefaction-of-air sensation associated with explosive soundtrack effects
• Subsonic Filter: All-analogue
• Subsonic Filter Operating Point: Begins as low as 8 Hz
• Subsonic Filter Purpose: Reduces infrasonic soundtrack noise extending below the driver's resonance point
• Maximum-Performance Objective: Designed to play to the driver's limits while minimizing distortion
• Output Improvement: Approximately 50% louder than the predecessor
• Relative Output Claim: 6 dB louder than previous REL models within 50% of its price, as stated in the supplied product information
• Performance Positioning: Output levels described as comparable to models priced well above $1,000/£1,000
• Cabinet Construction: Right-sized and solidly braced
• Cabinet Proportions: Lower and sleeker than the previous design
• Cabinet Design Influence: REL Reference models
• Cabinet Body Finish: Horizontally streaked, line-grained black composite
• Cabinet Appearance: Black aluminum-look finish
• Top Panel Thickness: 12 mm
• Top Panel Finish: Hand-polished piano-black lacquer
• Lacquer Process: Five coats
• Top Panel Function: Helps damp vibration on the cabinet's critical upper surface
• Logo Treatment: Discreet REL logo appearing within the top lacquer finish
• Primary Signal Application: .1/LFE
• Wired Connection Referenced: RCA
• Wireless Option: Optional REL HT-Air™
• HT-Air Wireless Frequency: 5.8 GHz
• HT-Air Maximum Range: Up to 60 feet
• HT-Air Compression: No digital compression
• HT-Air Hardware: Compact transmitter and matching receiver
• HT-Air Chipset: LSIC chip related to the technology used in REL AirShip II
• HT-Air Conversion Architecture: Omits the more expensive analogue-to-digital and digital-to-analogue converters used in AirShip II
• HT-Air Intended Signal: .1/LFE signals using RCA connectivity
• System Integration: Can supplement the .1/LFE output of systems using REL Reference, Serie S, or T/i subwoofers
• Immersive System Compatibility: Can be combined with Serie T/x or Serie S models in REL HT/3D™ installations
• Performance Character: High-output, fast, fluid, precise bass
• Home Theater Benefit: Designed for powerful, chest-rumbling special effects
• Music Performance: Powerful, robust, controlled bass suitable for musical applications

REL HT/1205 MKII Q&A:

What is the REL HT/1205 MKII designed for?

The HT/1205 MKII is primarily designed as a high-performance home theater subwoofer for .1/LFE reproduction. Its 12-inch CarbonGlas™ driver, 500-watt Class D amplifier, and home theater-specific PerfectFilters™ circuitry are optimized for the deep, dynamic bass found in movie soundtracks.

How powerful is the REL HT/1205 MKII?

The HT/1205 MKII uses a 500-watt Class D amplifier with MOSFET power modules rated at 800 watts. This provides significant operating headroom for demanding low-frequency transients.

How much more powerful is the HT/1205 MKII than the previous HT/1205?

REL states that the HT/1205 MKII can play approximately 50% louder than its predecessor while also delivering greater precision and subtlety. The supplied information also describes its output as 6 dB greater than previous REL models within 50% of its price.

How deep does the REL HT/1205 MKII play?

REL's dedicated home theater input filters are designed to deliver exceptionally flat bass extending into the 20 Hz range. An all-analogue subsonic filter begins as low as 8 Hz to reduce unwanted infrasonic soundtrack information below the driver's useful operating range.

What makes the CarbonGlas™ driver different?

The CarbonGlas™ driver combines a lightweight glass-fibre primary cone with a true carbon-fibre center cap for a stiff, controlled structure. Larger magnets and an upgraded suspension system increase output capability while helping the driver remain fast and controlled.

Is the HT/1205 MKII suitable for music as well as movies?

Yes. Although engineered primarily for home theater, its lightweight driver, analogue filtering, powerful amplification, and controlled cabinet allow it to reproduce music with speed, weight, and articulation.

Can the REL HT/1205 MKII be used wirelessly?

Yes. The optional REL HT-Air™ system uses an uncompressed 5.8 GHz wireless connection to transmit .1/LFE signals up to 60 feet, reducing the need for long RCA cable runs.

Can the HT/1205 MKII be combined with other REL subwoofers?

Yes. It can supplement the .1/LFE output of systems using REL Reference, Serie S, or T/i subwoofers and can be combined with Serie T/x or Serie S models in larger REL HT/3D™ immersive home theater configurations.

REL HT/1205 MKII Downloads:

REL HT/1205 MKII Manual