Martin Audio SXH218 subwoofer

Martin Audio SXH218 subwoofer is the top choice for sound systems that require powerful, deep and precise bass. Developed by Martin Audio (UK), the SXH218 delivers outstanding performance for stages, clubs, auditoriums and high-end business karaoke systems, helping to reproduce powerful, widespread and well-controlled bass — true to professional sound standards.

General introduction about Martin Audio SXH218 subwoofer

Martin Audio SXH218 is a High Power Ground-Stacked Subwoofer designed for professional sound systems, outdoor stages, concert halls and high-end clubs. With its exclusive Hybrid® horn/reflex structure, the SXH218 delivers outstanding sound performance in the deep bass range, while maintaining accuracy, speed of response and extremely high SPL.

The loudspeaker is designed in a ground-stacked style, allowing for flexible and stable deployment in PA line array systems or standalone sub systems. Thanks to the use of 18” neodymium drivers with dual 4.5” voice coils, the SXH218 achieves maximum power while ensuring light weight, good heat dissipation and extremely low distortion – ideal conditions for systems requiring deep bass, strong force and high durability.

Outstanding product specifications:

• Ultra high power ground stacked subwoofer: Ground-stacked design allows for direct placement on the floor or stacking of multiple subs to create high sound pressure (SPL over 145 dB), suitable for outdoor performances, stages and festivals.
• Hybrid® horn/reflex loading for maximum sonic performance and low frequency extension: Hybrid horn/reflex construction combines the amplification performance of a horn and the deep frequency extension of a bass reflex, delivering bass down to 30 Hz while maintaining high sensitivity.
• Dual 18” (460mm)/4.5” (115mm) voice coil neodymium drivers: 18-inch driver with large diameter dual voice coil for increased heat resistance, better diaphragm travel control and lower distortion at high power levels; neodymium magnet reduces weight while ensuring strong magnetic force.
• Forward or backward movement: The SXH218 can be configured in cardioid mode, which means the speaker is turned upside down to cancel out the sound behind the stage, reducing echoes and controlling the bass delivery more precisely — very important in professional line array systems.

Detailed review of the outstanding features and characteristics of the Martin Audio SXH218 subwoofer

In the world of professional audio, Martin Audio SXH218 subwoofer is considered a symbol of power and precision in the bass range. The product not only delivers extremely deep and powerful bass, but also demonstrates the ability to control low frequencies delicately, serving well for performance systems, large stages and high-end business karaoke systems. Exclusive Hybrid® design - reproduces deep, powerful bass and absolute control

The most prominent highlight of Martin Audio SXH218 is the Hybrid® (Horn/Reflex) subwoofer design – a combination of two acoustic operating principles: horn-loaded for high sound pressure and bass reflex for extended sub-bass frequency range.

This structure allows SXH218 achieves maximum performance while ensuring extremely low THD, resulting in powerful and clear bass. When operating, sound energy is compressed and released with high pressure, creating a distinct “floor shaking” feeling without any background hum.

Sensitivity over 108 dB SPL and the ability to reach a maximum sound pressure level of up to 145 dB SPL make the SXH218 the perfect choice for sound systems that require deep bass coverage, especially in large stages, bars/clubs, tea rooms and high-end business karaoke systems.

The Hybrid® structure also helps reduce resonance and phase distortion in the low frequency range, providing tight, compact, well-controlled bass that does not "flatten" when combined with full-range speakers.

Dual 18-inch neodymium drivers – powerful performance, fast response and super durability

Inside the Martin Audio SXH218 are two premium 18-inch (460 mm) bass drivers, equipped with dual 4.5-inch (115 mm) voice coils for increased heat dissipation and more precise diaphragm travel control.

Neodymium – typically found in high-end performance speakers – delivers a 30–40% stronger magnetic field than ferrite, while being significantly lighter. This makes the SXH218 both powerful and portable, making it ideal for mobile audio systems.

Dual coil structure and intelligent cooling system help the speaker maintain stable performance for a long time without losing quality. When combined with a power amplifier Martin Audio iK42 or equivalent power lines, Martin Audio SXH218 can achieve even, deep, and extremely precise bass coverage — the key factor in helping the audience “feel” the bass, not just “hear” it.

Flexible front-rear configuration for any acoustic space

Martin Audio SXH218 allows users to choose between front-firing or cardioid operation – a rare find in dual 18-inch subwoofers.

When the speaker is set in cardioid mode, the low frequency energy emitted back is largely eliminated, reducing the excess bass in the area behind the speaker by up to 20–25 dB, limiting the stage "hum" or echo that causes fatigue for singers and musicians.

This mode is especially useful for large karaoke rooms, stages or closed halls, where reflected sound easily thickens the bass. Conversely, with the front-facing configuration, Martin Audio SXH218 maximizes compression force, suitable for open spaces or outdoor stages that require high negative pressure.

Thanks to this flexibility, the technician can fine-tune the bass direction according to the space characteristics without the need for additional complex processing equipment.

Super durable mechanical structure – optimized operation and movement

Martin Audio SXH218 Made of 18-21 mm thick multi-layer birch plywood, coated with scratch-resistant and moisture-proof Polyurea paint, ensuring high durability in harsh environments, even when used continuously on outdoor stages.

The speaker enclosure is reinforced with a steel handle system, moving wheels and standard stacking joints, allowing for easy ground stacking while maintaining stability and safety.

The reflex port is designed to optimize airflow, reducing air turbulence and phase distortion when the speaker operates at high pressure levels. The result is subwoofer Martin Audio SXH218 can operate stably for hours while still maintaining solid bass, without "hum".

It is this combination of solid mechanical construction and precise acoustic design that gives the speaker exceptional durability, making it a worthy long-term investment in professional sound systems.

Maximum electroacoustic performance – clean sound, studio-grade control

The SXH218 is tuned for optimal performance in the temperature range of 0–45°C, well adapted to the hot and humid conditions typical of Vietnam. Low power consumption but high acoustic efficiency, along with extremely low THD (Total Harmonic Distortion) index, helps the sound to be emitted faithfully, without distortion even at maximum SPL.

High sensitivity, low noise floor and extended frequency reproduction help the SXH218 deliver rich, powerful and accurate bass. When paired with Martin Audio WPM, WPS or CDD-LIVE full-range speakers, the system achieves absolute coherence, in-phase sound, even and powerful bass coverage.

Practical application & standard technical matching of Martin Audio SXH218 subwoofer

With powerful Hybrid® design, huge power and accurate bass reproduction, Martin Audio SXH218 Not only suitable for stage performances but also easy to integrate into many different sound systems.

• Paired with Martin Audio WPM/WPS full-range speakers in a line array: The SXH218 works perfectly when combined with WPM or WPS line array modules, extending the frequency range down to 30Hz, adding background power to live music and DJ sets.
• Used in high-end business karaoke systems or large tea rooms: When tuned by a dedicated DSP or digital reverb like the JBL VX9, the speaker delivers tight, deep bass without causing background noise, suitable for spaces with thick soundproofing.
• Pair with Martin Audio iK42 or iK81 power amplifier: The iK series amplifiers support high power, high damping factor, precise 18” driver control, maintain good linearity at high SPL and reduce signal distortion clipping.
• Cardioid sub array installation (front-rear direction): When arranged in a cardioid 2 or 3 speaker configuration, the SXH218 suppresses rear anti-phase bass by up to 25 dB, reducing stage “rumble” and increasing mid-range clarity.
• Incorporate into outdoor stage or festival sound systems: Extremely large output power, maximum SPL of 145 dB, and bass direction ability help SXH218 meet events of several thousand people while still maintaining clean sound.
• Applications in halls, theaters or event centers: Low distortion (THD <0.5%) and low noise floor ensure faithful, balanced sound with mid-highs, avoiding the phenomenon of "bass overpowering sound".

Where to buy cheap, genuine, high-end Martin Audio SXH218 subwoofer?

If you are looking for where to buy Martin Audio SXH218 subwoofer genuine, good price and full warranty, then Phuc Truong Audio is a reliable choice. As an agent specializing in providing professional audio equipment in Ho Chi Minh City, Phuc Truong Audio distribution subwoofer Martin Audio SXH218 Officially imported, with CO-CQ, inspection stamp, genuine warranty and on-site installation and calibration service.

Customers can listen directly at the showroom to feel the deep bass, power and frequency accuracy of the SXH218 when combined with a full speaker system. Martin audio or iK42 amplifier. With experience in constructing hundreds of high-end karaoke systems, stages and halls, Phuc Truong Audio's technical team will help you choose the optimal configuration, ensuring powerful performance - British standard sound - durable over time.

Frequently asked questions about Martin Audio SXH218 subwoofer

Is the Martin Audio SXH218 subwoofer suitable for use in business karaoke systems?

Yes. Martin Audio SXH218 is a very high-power subwoofer, using a Hybrid® horn/reflex structure to reproduce deep and powerful bass, very suitable for high end business karaoke system, VIP room or mini stage. When combined with full speaker Martin Audio Blackline or TORUS series, the system will produce solid, thick bass that spreads evenly throughout the room.

Can the Martin Audio SXH218 subwoofer be used with the JBL VX9 or Eudac CL15A digital echo in a karaoke system?

Absolutely. When using digital echo has the ability to cut frequencies and adjust crossovers precisely as JBL VX9 digital echo or Eudac KM600, you can adjust the crossover frequency of SXH218 in the range of 80-120Hz so that the sub blends smoothly with the full-range speaker, avoiding overlapping ranges causing hum or bass resonance.

Does the Martin Audio SXH218 subwoofer need anti-feedback treatment when used with a karaoke microphone?

No need for separate anti-howling subwoofer, but the system should use digital echo or mix Has a feedback suppressor function to control the entire range. Because howling usually comes from the mid-high range, but when the sub hits too hard or resonates with the floor, it can still create slight feedback.

Do I need to use a separate UPS or voltage stabilizer for the SXH218 amplifier?

Very necessary. When the sub operates at high level, the current consumption is large. A UPS or voltage stabilizer with capacity of 3000-5000VA will help stabilize the voltage, avoid voltage drops that cause bass loss or clipping. ampli.