Our workhorse sub, the dual 18-inch hs-28 deploys our patent-pending ACM (Active Compliance Management) technology, which combines both band-pass and vented alignments into a single enclosure. The hs-28 places two premium, 18-inch transducers into this configuration, with both woofers sharing a common vented chamber. One woofer’s frontal radiation is direct, while the second woofer’s frontal radiation drives the band-pass chamber.
From there we add active onboard electronics including dual monaural powerful amplifiers that send 830W of pure sine wave power (2000W “peak” ) to each woofer. Sophisticated DSP precisely aligns the phase arrivals of the front facing woofer and both vents.

Features
- Active Compliance Management: Patent-pending hybrid design combines both band-pass and vented alignments into a single, compact footprint for more output and definition.
- Tons of horsepower: Dual amplifier modules supplies 830W pure sine wave power (2000W “burst” power) to each woofer (4000W ‘burst’ total.)
- Purpose-designed transducers: Dual spider long excursion woofers features large, 4-inch voice coils for increased power handling and reduce power compression.
- Standard IP for easy networking onboard: .Simply plug in, and the system automatically connects to virtually any kind of IP configuration.
- SystemVUE software: Mac, iOS and Windows compatible software provides access to networks and device-level parameters such as speaker protection, input/output levels, volume, mute, delay and input sources.
- Built for the road: Premium birch plywood enclosure with extensive internal bracing and a highly-durable Dura Coat finish.
- Impressive output-to-size ratio: Ideal for building extremely high-output and compact subwoofer arrays.

Applications
- Portable and installed live performance venues
- High-impact audio/visual presentations
- Theatrical sound design
- World class dan
ce clubs - Sound reinforcement rental companies
- Performing arts centers
- Themed entertainment facilities

The unique ACM configuration requires a highly-capable transducer. The precision-engineered, long excursion 18-inch woofer developed for the hs-28 features large, 4-inch voice coil for increased power handling and decreased power compression.
The combination of ACM, purpose-designed transducers, and precision electronics allows the hs-28 to deliver much higher output throughout its operating bandwidth from a footprint that’s smaller than most dual 18-inch vented designs.

Rugged Design and Stage Ready
What’s more, the small frontal area and footprint of the hs-28 makes it incredibly easy to assemble compact subwoofer arrays. For example, a stack of six hs-28’s is only slightly more than 6 feet wide by 5 feet high and produces more than 142 dB SPL at one-meter maximum output. The hs-28’s very linear and consistent response makes it an ideal component in directional subwoofer arrays including cardioid stacks and end-fire arrays.

Like all h-Class systems, the hs-28 ships with networking capabilities already onboard. There’s no need for additional cards or retrofitting. SystemVUE uses standard IP protocols to simplify the networking process. Simply plug in and the hs-28 will automatically connect to virtually any kind of IP configuration. Users can then access and monitor network and device-level parameters through our SystemVUE software.
We’ve housed all this rich, subwoofery-goodness in a rugged enclosure that’s manufactured from premium-grade, birch plywood with extensive internal bracing for resonant free operation. A highly-durable, 6-step Dura Coat finish looks great and protects the hs-28 through many years on the road.
