Seismix 5

Krix Seismix 5 Active Subwoofer

Powerful 12-Inch Active Subwoofer for Serious Home Cinema

The Krix Seismix 5 Active Subwoofer is designed for home cinema systems that demand deep, powerful and controlled low-frequency performance.

Featuring a 305mm (12-inch) long-throw woofer and a powerful 450-watt RMS amplifier, the Seismix 5 delivers the scale, depth and impact required to bring movie soundtracks, music and low-frequency effects to life.

With an impressive 15Hz–200Hz in-room frequency response and maximum output of 125dB SPL, the Seismix 5 is engineered for serious home theatre installations where cinematic bass performance is a priority.

Highlights & Benefits

• 305mm (12-inch) long-throw woofer — delivers deep and powerful low-frequency performance.

• 450W RMS amplification — provides substantial power for demanding home cinema soundtracks.

• 15Hz–200Hz in-room response — reaches exceptionally deep into the low-frequency spectrum.

• 125dB maximum SPL — high-output bass for serious home cinema systems.

• Bass-reflex enclosure — front-vented design supports extended low-frequency reproduction.

• 50mm (2-inch) long-throw voice coil — developed for high-level low-frequency reinforcement.

• Balanced XLR input — provides flexible connectivity for premium AV processors and installations.

• Stereo RCA inputs — easy integration with conventional AV receivers and Hi-Fi systems.

• Continuously variable phase — adjustable from 0° to 180°.

• Adjustable low-pass filter — variable from 50Hz to 200Hz or completely bypassable.

• USB-C power output — supplies 5V/1A for an optional wireless receiver.

• Automatic signal sensing — enters standby after 15 minutes without an input signal.

• Australian made — engineered and manufactured by Krix in Australia.

Powerful 12-Inch Long-Throw Woofer

At the heart of the Seismix 5 is a nominal 305mm (12-inch) paper-cone driver with a 50mm (2-inch) long-throw voice coil.

The driver has been developed specifically for high-level, low-frequency reinforcement, allowing it to move substantial amounts of air while maintaining the control required for demanding home cinema content.

From explosive action sequences to deep soundtrack effects and music, the Seismix 5 is designed to reproduce low frequencies with authority and scale.

450-Watt RMS Amplification

The Seismix 5 incorporates a powerful Class D amplifier module rated at 450 watts RMS.

Its integrated active architecture allows the amplifier and woofer to operate as a matched system, providing the power and control required to achieve a maximum in-room output of 125dB SPL.

Deep Bass Down to 15Hz

With an in-room frequency response extending from 15Hz to 200Hz, the Seismix 5 reaches into the ultra-low-frequency region responsible for the physical impact of cinematic effects.

This deep extension helps reproduce explosions, thunder, musical scores and other low-frequency effects with greater realism, scale and intensity.

125dB Maximum In-Room Output

The Seismix 5 is rated to deliver up to 125dB maximum SPL in-room, making it well suited to dedicated home cinemas and larger entertainment spaces.

Its combination of high output and deep extension allows it to deliver powerful bass while retaining the control required for subtle soundtrack details and music.

Front-Vented Bass-Reflex Enclosure

The Seismix 5 uses a front-vented bass-reflex enclosure designed to extend low-frequency output and provide practical placement flexibility.

Because the vent is positioned at the front of the cabinet, the subwoofer can be easier to integrate into dedicated cinema installations where rear clearance may be limited.

RCA & Balanced XLR Connectivity

For greater installation flexibility, the Seismix 5 provides both stereo line-level RCA inputs and a balanced XLR input.

The balanced connection is particularly useful in premium home cinema installations where longer cable runs may be required between the AV processor or receiver and the subwoofer.

Adjustable Phase Control

A continuously variable 0° to 180° phase control allows the Seismix 5 to be better aligned with the main loudspeakers and its position within the room.

Correct phase adjustment can help create a smoother transition between the subwoofer and the rest of the system for more cohesive low-frequency reproduction.

Adjustable Low-Pass Filter

The built-in low-pass filter can be adjusted from 50Hz to 200Hz or completely bypassed.

Bypass mode is particularly useful with AV receivers and processors that already manage crossover frequencies and bass distribution internally.

Optional Wireless Receiver Support

The Seismix 5 includes a USB-C connection providing 5V/1A, designed to supply power to an optional wireless receiver.

This provides additional installation flexibility when running a conventional audio cable between the AV system and subwoofer is difficult or undesirable.

Automatic Signal-Sensing Power

For convenient everyday operation, the Seismix 5 incorporates signal-sensing automatic power control.

When no input signal is detected for approximately 15 minutes, the subwoofer automatically switches to standby.

Premium Finish Options

The current Krix product page lists the Seismix 5 in the following finishes:

These options allow the subwoofer to complement a wide range of Krix loudspeaker systems and interior styles.

Australian Designed & Manufactured

The Krix Seismix 5 is engineered and manufactured in Australia.

Krix has been producing loudspeakers in Australia since 1974, and the Seismix 5 applies the company's cinema loudspeaker expertise to a powerful active subwoofer designed for high-performance home entertainment systems.

Why Choose the Krix Seismix 5?

The Krix Seismix 5 Active Subwoofer is an excellent choice for customers building a serious home cinema system and wanting substantially deeper bass and higher output than smaller compact subwoofers can provide.

With a 12-inch long-throw woofer, 450W RMS amplification, bass extension down to 15Hz, 125dB maximum output, balanced XLR connectivity and flexible crossover and phase adjustment, it provides the foundation required for powerful cinematic sound.