HK Audio LINEAR 9 118 Sub A 18" Active Subwoofer

HK Audio LINEAR 9 118 Sub A

The HK Audio LINEAR 9 118 Sub A combines 1100W Class-D amplification with an 18-inch woofer featuring a 4-inch voice coil, delivering 131dB peak SPL while extending down to 38Hz (-10dB). Built in a bass-reflex enclosure that keeps weight to just 91.5 pounds, this subwoofer balances output capability with transport practicality. Network-controllable DSP via Ethercon provides comprehensive processing including 10-band parametric EQ, delay, limiting, and polarity control, with front-panel access to cardioid presets (1:1 and 2:1) that simplify directional bass deployment. The 96kHz converters with less than 2.6ms latency maintain timing accuracy for live performance, while the dedicated DSP output integrates non-networked speakers into controlled systems.

In touring and installed applications, the LINEAR 9 118 Sub A's stereo preamplifier supports true 2.1 system configurations, maintaining separate left/right channels through to the outputs. The cardioid presets automatically generate phase-delayed signals for rear-firing subs, eliminating manual calculation and routing complexity when building directional arrays. PowerCon NAC3 in/thru connections simplify power distribution in multi-sub setups, and the birch multiplex cabinet with PU coating survives repeated load-ins. The M20 pole mount supports stacking mid/high units directly on the subwoofer for compact system footprints. Made in Germany with attention to construction details and component quality, this subwoofer delivers reliable performance in professional environments where failure isn't an option. Explore our powered subwoofers for more networked bass solutions.

1100W Class-D Power In Efficient Bass-Reflex Design

The 1100W RMS Class-D amplifier drives the 18-inch woofer with 4-inch voice coil to 131dB peak SPL, providing enough output for mid-sized venue systems and touring applications. The bass-reflex tuning optimizes efficiency in the 42-100Hz range, allowing the cabinet to produce high SPL without requiring excessive amplifier power or massive enclosure volume. Frequency response extends to 38Hz at -10dB, covering the fundamental bass range for electronic music, kick drums, and bass guitar without rolling off prematurely. The compact 21.7" x 22.1" x 27.2" dimensions and 91.5-pound weight make single-person transport practical, while the birch multiplex construction with PU coating maintains structural integrity through repeated gigging. The bass-reflex port tuning focuses on controlled output rather than excessive boom, so low-frequency content maintains definition instead of turning into indistinct rumble. 

Front-Panel Cardioid Presets Simplify Directional Arrays

Direct access to cardioid 1:1 and 2:1 presets via front-panel controls eliminates the laptop-and-network requirement for quick directional bass setups. The 1:1 cardioid mode uses two subs—one forward-firing, one rear-firing with phase-delayed signal—to create front-focused bass patterns that reduce stage wash and rear reflections. The 2:1 mode uses two forward subs and one rear sub for asymmetrical cardioid patterns with greater front-to-back rejection. These presets automatically generate the correct phase relationships and delay timing, so you're deploying cardioid arrays without calculating milliseconds or worrying about polarity mistakes. The dedicated DSP output provides the processed signal for feeding rear-firing subs or integrating non-networked speakers into controlled systems. This becomes critical when you need cardioid coverage but don't have matching network-capable subwoofers, or when integrating the LINEAR 9 into existing systems with mixed speaker types.

Network-Controllable DSP With Professional Processing

Ethercon RJ45 connectivity (in/thru) enables remote control via HK Audio's DSP CONTROL software for Windows and macOS. The onboard DSP platform runs at 96kHz sample rate with less than 2.6ms system latency—low enough for live performance where timing between subs and tops matters. Fully parametric 10-band EQ with variable filter characteristics provides surgical control over room modes and system tuning, while independent low-pass filtering, polarity control, level adjustment, delay (for time-alignment), and limiting protect the driver and optimize system response. The stereo preamplifier maintains separate left and right channels, supporting true stereo 2.1 configurations rather than forcing mono summation at the sub. This matters in installed systems or DJ applications where maintaining stereo imaging through the low frequencies preserves spatial information. PowerCon NAC3 in/thru connections simplify power distribution across multi-sub arrays, and the lockable connectors prevent accidental disconnection during shows. Made in Germany with attention to component quality and construction standards, the LINEAR 9 118 Sub A delivers reliable performance in professional touring and rental applications.

Highlights

• 1100W RMS Class-D amplifier drives 18-inch woofer with 4-inch voice coil to 131dB peak SPL
• Bass-reflex design extends response to 38Hz (-10dB) in compact 91.5-pound enclosure
• Front-panel access to cardioid 1:1 and 2:1 presets for quick directional bass deployment
• Network-controllable DSP (96kHz, <2.6ms latency) with 10-band parametric EQ and comprehensive processing
• Dedicated DSP output integrates non-networked speakers and provides processed signal for cardioid arrays
• Stereo preamplifier maintains separate L/R channels for true 2.1 system configurations
• Birch multiplex construction with PU coating and lockable PowerCon/Ethercon connections

Technical Specifications

What's in the Box