Hertz CS 250 S4 – 10" Subwoofer (4-Ohm)

Hertz CS 250 S4 – 10" Sealed-Box Subwoofer for Tour-Pak, Trike and Custom Harley Enclosures

The Hertz CS 250 S4 is a conventional 10″ subwoofer from the Cento range, built for builds that can provide a properly designed sealed enclosure. Hertz optimises its electroacoustic design for sealed boxes starting from 16 litres, and pairs it with a mono amplifier in the 300–400 W RMS region. It is the sensible traditional-subwoofer choice for Tour-Pak, trike and custom-box installs where the airspace genuinely exists.

Who This Is For

The CS 250 S4 suits riders building a Tour-Pak subwoofer, a trike boot install, or a fabricated bass box where the enclosure can be built to specification. It is not the right driver for a standard saddlebag you still want to use for luggage: 16 litres is not a large car-audio box, but it is meaningful volume once you try to package it inside a Harley bag. If mounting depth or enclosure volume is your real constraint, the Hertz MPS 250 S4 is the ultra-shallow alternative at 82.6 mm depth. If you need serious low-frequency output from a saddlebag rather than a purpose-built box, a large-format motorcycle mid-bass driver such as the Cicada CMB8.S4 is the better tool.

What This Is Best For

• Properly designed sealed enclosures from 16 litres – Hertz states the driver's electroacoustic design is optimised for sealed boxes starting at 16 litres (0.57 cu ft). Build to that and the response arrives as designed. Starve it of volume and the low end simply will not develop. On the road: a Tour-Pak or custom box built to specification delivers smooth, controlled low end rather than the thin, peaky result an undersized enclosure produces.
• Moderate mono amplifier pairing at 300–400 W RMS – At 300 W continuous and a single 4 Ω voice coil, this driver is straightforward to wire and does not demand a high-output electrical upgrade. Matching the amplifier to the driver rather than overpowering it is what keeps it reliable. On the road: usable bass without rebuilding the charging system to support it.
• 12.5 mm Xmax for controlled excursion – Hertz publishes 12.5 mm of linear excursion, which is what allows a 300 W driver to produce genuine bottom-octave output in a correctly sized sealed box. On the road: low-frequency content stays clean at volume instead of hardening as the driver runs out of travel.
• Polypropylene cone with a durable surround – A polypropylene diaphragm is dimensionally stable across temperature and resistant to moisture, which matters for any driver living in a motorcycle enclosure through Australian summers and wet winters. On the road: consistent performance from a cold morning start through a hot afternoon run, without the compliance changes that degrade cheaper materials over time.
• 115 mm mounting depth – Shallow enough for many purpose-built motorcycle enclosures, though it still needs the enclosure volume behind it. Confirm both depth and airspace before committing to a design. On the road: fits the kind of fabricated enclosure a good installer builds, provided the box is designed around the driver rather than the other way round.

Recommended System Use

• Tour-Pak subwoofer enclosures built to 16 litres or greater
• Trike boot and rear-compartment installs
• Custom fabricated sealed bass boxes
• Balanced systems seeking smooth low-end reinforcement rather than maximum SPL
• Mono amplifier pairing at 300–400 W RMS

Fitment

• Suitable for custom Harley-Davidson® Touring enclosures where the required volume can be provided
• Compatible with motorcycle-specific sealed boxes from various manufacturers
• Works with Tour-Pak, trike and custom-box layouts