The REL HT/1003 MKII is a compact high-performance powered subwoofer featuring a 10-inch CarbonGlas™ driver and 300-watt RMS Class D amplifier. Delivering more than 10 dB greater output than the original HT/1003, it produces powerful, controlled bass for movies, gaming, and music. REL PerfectFilter™ analogue circuitry, adjustable 30–200 Hz crossover, LFE and stereo RCA connectivity, and optional HT-Air™ wireless capability provide precise and flexible system integration. Premium cabinetry and compatibility with REL Serie T/x, Serie S, and HT/3D™ systems make the HT/1003 MKII an excellent choice for serious home theater systems where space is at a premium.
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REL HT/1003 MKII

The REL HT/1003 MKII, nicknamed “The Hammer,” delivers formidable home theater bass from a compact enclosure designed for rooms where space is limited but performance expectations are not. Built with the same attention to cabinet construction, finish, and engineering found in REL’s larger HT models, the HT/1003 MKII combines a powerful 300-watt RMS Class D amplifier with a 10-inch (250mm) CarbonGlas™ long-throw driver for deep, fast, high-output bass.

Compared with the original HT/1003, the MKII delivers more than 10 dB of additional usable output—approximately twice the perceived loudness—providing substantially greater headroom for movie soundtracks, gaming, and dynamic music. A larger motor system, upgraded suspension, enlarged surround, improved power supply, and refined amplifier architecture help the subwoofer remain controlled even as output approaches the limits of the driver.

REL’s PerfectFilter™ analogue circuitry further improves performance by extending deep bass response and allowing useful energy to reach higher into the frequency range. The refined secondary filtering gives cinematic effects greater impact and realism, while an all-analogue subsonic filter begins as low as 12 Hz to reduce potentially damaging infrasonic soundtrack information below the driver’s useful operating range.

Despite its strong emphasis on home theater, the HT/1003 MKII is engineered to deliver fast, fluid, musical bass as well. Its lightweight yet rigid CarbonGlas™ cone combines a glass-fiber primary cone with a true carbon-fiber center cap to produce controlled pistonic movement with low unwanted coloration.

The cabinet receives the same premium treatment as the rest of REL’s MKII HT range. Its lower, sleeker proportions are inspired by REL Reference designs and are intended to support faster, deeper bass presentation while integrating visually with Serie T/x and Serie S models. Five coats of hand-polished piano-black lacquer finish the top panel, with a discreet REL logo beneath the lacquer and a horizontally streaked, line-grained composite cabinet body.

For installation flexibility, the HT/1003 MKII provides dedicated .1/LFE and stereo low-level RCA connectivity, RCA outputs for daisy-chaining additional REL subwoofers, a variable 30–200 Hz crossover, 0/180-degree phase control, adjustable level, and selectable standby or always-on operation. Optional HT-Air™ wireless connectivity can transmit the LFE signal using an uncompressed 5.8 GHz wireless connection at distances of up to 60 feet, making it easier to position the subwoofer without a long signal cable.

What It's Good At:

• High-output home theater bass: More than 10 dB greater output than the original HT/1003 gives explosions, effects, and low-frequency soundtrack information considerably more scale and impact.
• Big performance in smaller rooms: The compact 10-inch design provides a strong alternative when a larger REL subwoofer is impractical or unnecessary.
• Fast, controlled bass: The CarbonGlas™ driver, larger magnet system, upgraded suspension, and enlarged surround maintain control at demanding playback levels.
• Music as well as movies: Refined amplification and analogue filtering improve speed, texture, and integration for two-channel music systems in addition to theater use.
• Flexible system integration: Dedicated LFE and stereo RCA inputs, variable crossover, adjustable level and phase, plus daisy-chain outputs support a variety of AV and stereo configurations.
• Premium REL system building: Its cabinetry visually complements Serie T/x and Serie S models and makes the HT/1003 MKII well suited to larger REL HT/3D™ multi-subwoofer systems.

REL HT/1003 MKII Full Specifications:

• Product: REL HT/1003 MKII
• Nickname: The Hammer
• Product Type: Powered home theater sub-bass system / subwoofer
• Enclosure Format: Compact, front-firing powered subwoofer design
• Active Driver: 10-inch (250mm) CarbonGlas™ driver
• Cone Construction: Glass-fiber primary cone with true carbon-fiber center cap
• Driver Motor: Upgraded larger, more powerful magnet system
• Suspension: Upgraded suspension with enlarged surround for increased driver travel
• Amplifier Power: 300 watts RMS continuous
• Amplifier Type: Class D
• Amplifier Updates: Thicker circuit boards and upgraded power supply
• Output Improvement: More than 10 dB higher output than the original HT/1003
• Perceived Output Increase: Approximately twice as loud as the original HT/1003
• Filtering: REL PerfectFilter™ all-analogue filtering
• Secondary Filtering: Revised higher-frequency secondary filter architecture
• Deep-Bass Filtering: Analogue elevation filtering designed to extend deep-bass performance
• Subsonic Filtering: All-analogue subsonic filter
• Subsonic Filter Operation: Begins as low as 12 Hz and reduces infrasonic information below the driver’s useful operating range
• Integrated Protection: Filtering and limiting designed to allow high output while protecting the driver from damaging ultra-low-frequency content
• Crossover: Variable 30–200 Hz
• Phase Control: 0° / 180°
• Level Control: Variable input level / volume
• Operating Modes: Standby or Always On
• Low-Level Inputs: Left and right RCA
• Home Theater Input: Single RCA .1/LFE input
• Low-Level Output: RCA output connections for connection of additional REL subwoofers
• Daisy-Chaining: Supported through RCA output-to-input connections
• Theater Connection: RCA connection from processor or AV receiver Sub Out to the .1/LFE input
• Stereo Connection: Stereo RCA connection from a preamplifier, processor, powered speaker system, or compatible source
• Wireless Capability: Optional REL HT-Air™
• HT-Air Wireless Frequency: 5.8 GHz
• HT-Air Wireless Range: Up to 60 feet
• HT-Air Signal Handling: Wireless transmission without digital compression
• HT-Air Technology: Uses an LSIC chip related to the technology used in REL AirShip II
• Wireless Primary Application: .1/LFE signal transmission via RCA connection
• System Compatibility: Designed to visually integrate with REL Serie T/x and Serie S
• Multi-Subwoofer Application: Compatible with REL HT/3D™ system configurations
• Top Panel Finish: Five coats of hand-polished piano-black lacquer
• Logo Treatment: Discreet REL logo beneath the top lacquer layer
• Cabinet Body Finish: Horizontally streaked, line-grained composite
• Cabinet Styling: Lower, sleeker proportions influenced by REL Reference models
• Fuse Rating at 230 V: 2.5 A
• Fuse Rating at 120 V: 4 A
• Maximum Specified Ambient Operating Temperature: 86°F / 30°C
• Ventilation Requirement: Minimum 10 cm clearance around the apparatus

REL HT/1003 MKII Q&A:

Is the REL HT/1003 MKII powerful enough for home theater?

Yes. The HT/1003 MKII combines a 300-watt RMS Class D amplifier with a 10-inch CarbonGlas™ driver and delivers more than 10 dB greater output than the original model, giving movies and effects substantially more impact and headroom.

Who is the HT/1003 MKII best suited for?

It is ideal for listeners who want serious REL home theater performance but do not have the room—or the need—for one of REL’s larger HT subwoofers.

Can the REL HT/1003 MKII be used for music as well as movies?

Yes. Although optimized for powerful theater performance, the MKII upgrades to its driver, amplifier, and analogue filtering also make it significantly more capable with music, delivering fast and controlled low-frequency reproduction.

What kind of driver does the HT/1003 MKII use?

It uses a 10-inch (250mm) CarbonGlas™ driver combining a glass-fiber primary cone with a true carbon-fiber center cap, upgraded magnet structure, and increased suspension travel.

How does the HT/1003 MKII connect to a home theater receiver or processor?

For home theater, a single RCA cable can connect the receiver or processor’s Sub Out to the HT/1003 MKII’s dedicated .1/LFE input. Stereo RCA inputs are also available for compatible two-channel systems and powered speakers.

Can multiple REL HT/1003 MKII subwoofers be connected together?

Yes. RCA output connections allow another REL subwoofer to be connected in parallel using REL’s daisy-chain configuration.

Does the HT/1003 MKII support wireless operation?

Yes, with the optional REL HT-Air™ wireless system. HT-Air uses a fast 5.8 GHz connection to carry an uncompressed signal up to 60 feet, reducing the need for long RCA cable runs.

Can the HT/1003 MKII be used in a REL HT/3D system?

Yes. Its performance and cabinet styling are designed to complement REL Serie T/x and Serie S products, making it suitable for larger, immersive REL HT/3D™ installations.

REL HT/1003 MKII Downloads:

REL HT/1003 MKII Manual