(February 26, 2026) Back in mid December, we introduced HYPERSUB and its Frontier Series launch, outlining the philosophy behind three purpose-built models designed around measurable in-room performance. Today, we get a closer look at one of those models, the F-21, a four-cabinet, system-level approach aimed squarely at modern immersive theaters that demand predictable output.
HYPERSUB says the F-21 is designed to deliver maximum linear output beyond 120dB while flexing extension down to a room-rattling 20Hz. It’s a complete four-cabinet sealed system, with each enclosure built around a 21" long-stroke carbon-fiber driver. All four drivers are powered and managed by a rack-mount HYPERSUB 422D amplifier, which delivers 4 × 2,200 watts RMS with the added advantage of individual DSP controls for each channel. This configuration, says HYPERSUB, allows integrators to treat the array as a mechanically and electrically coherent platform rather than four independent subs loosely grouped together.
Similar to other top-shelf CI-focused companies, HYPERSUB publishes verified output figures rather than estimates. According to its numbers, the F-21's linear SPL is rated at 122dB under AES75 testing at one meter in free space, with 128dB broadband peak measured under ANSI/CTA-2010B half-space conditions. Bandwidth is specified at 20–200Hz at -6dB relative to 100Hz, consistent with the system’s sealed alignment and focus on control rather than port-assisted extension.
As with all Frontier models announced in December, HYPERSUB’s engineering approach is a collaboration between Acoustic Frontiers and Harbottle Audio. The transducer is a custom 21" neodymium motor design offering more than 3" of linear excursion. The cabinets are built in Canada with void-free birch plywood and finished with real-wood veneer and beveled-edge detailing. Each system is verified to a 1% performance tolerance across more than 2,000 – yes, TWO thousand – quality control checkpoints, with validation performed through independent NWAA Labs testing aligned to AES75 and CTA-2010B methodologies.
Of course, when you start considering materials like birch ply and large, high-excursion drivers, you know your cabinetry is going to have some heft. Looking at factory specs, each F-21 cabinet measures 33-7/8" high × 25" wide × 17" deep and weighs 101 lbs. Big and heavy, yes, but note the 17" depth, which allows for behind-screen placement, wall-adjacent installation, or integration within cabinetry.
On the amplification side, the 422D houses four balanced XLR inputs and four SpeakOn outputs. DSP includes 10 bands of parametric equalization per channel, with bell, shelving, notch, and all-pass options, along with adjustable crossover points, delay, polarity, level, and limiting. The design is also intended to integrate cleanly with Trinnov Waveforming and Dirac ART room correction platforms, acknowledging that today’s reference theaters increasingly rely on multiple subwoofers working in coordinated arrays to smooth modal behavior and maintain seat-to-seat consistency. And that multi-sub approach is central to the F-21 concept. Rather than selling a single large enclosure and leaving layout decisions to chance, the system is designed as a four-sub array from the outset. For medium to large rooms, that configuration aims to simplify calibration and increase predictability when targeting RP-22 performance levels. For very large theaters, HYPERSUB notes that the F-21 can be combined with the company’s F-24 DUO infrasonic module to extend capabilities even further.
The HYPERSUB F-21 system is available now through HYPERSUB's dealer network at hypersubwoofers.com and is backed by a five-year warranty.
Related Reading:
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