HK Audio Linear Sub-4000A

With its 18-inch driver and 135 dB max SPL, this subwoofer is designed for large-scale sound reinforcement. It excels in professional environments like concert halls, large clubs, or outdoor events where you need significant low-end punch and deep bass extension.

No, it is an active subwoofer. It features an integrated Class D amplifier, meaning you can plug your signal directly into the unit without needing a separate power amp.

The unit features variable crossover points, allowing you to fine-tune the frequency handover between the sub and your top speakers. It also includes XLR Mid/High outputs, making it easy to route your signal through the sub and directly into your full-range cabinets.

Yes. It is built with a rugged birch multiplex enclosure and includes comprehensive active protection circuits. These features are specifically engineered to handle the rigors of professional use and ensure reliability during high-output performances.

The unit weighs 130.1 lbs (59 kg). Given its size and weight, it is a substantial piece of gear, so you will likely need a dolly or a second person to move it safely.

This specific enclosure design is optimized to maximize the efficiency of the 18-inch driver. It helps the subwoofer deliver a deeper, more powerful bass response compared to standard ported designs, making it ideal for demanding professional audio applications.