Cicada Audio CM8.4X — 8" Carbon Matrix Mid-Bass Motorcycle Speaker (4Ω) – 8-inch
| Size | 8 · Mid-bass |
| Impedance | 4 Ohm |
| Power | 250W RMS |
| Year Range | 2024+, 2014-2023 |
| Location | Saddlebags, Lower Fairing |
The CM8.2X at 4Ω — for bridged channels and conservative builds.
The Cicada Audio CM8.4X is an 8-inch 4Ω mid-bass component speaker — 250W RMS, 94 dB sensitivity, Carbon Matrix Composite™ (CMC™) cone, OFC copper shorting ring, Black Coat™ OFC 2.0-inch voice coil, N35SH neodymium motor, and a die-cast aluminium basket with Vortex Flow Venting™. Frequency response 70 Hz – 20 kHz (±3 dB). Sold in pairs.
The CM8.4X shares every construction element with the CM8.2X — the same CMC™ cone, the same OFC copper shorting ring, the same 250W RMS power handling, 94 dB sensitivity, and 70 Hz – 20 kHz frequency response in the 8-inch mid-bass component format. The 4Ω impedance presents a higher electrical load to the amplifier: lower current demand, reduced thermal stress, and compatibility with bridged configurations where a 4Ω minimum load is required.
Who This Speaker Is For
For builders running custom 8-inch speaker positions with bridged channels, or who prefer the conservative 4Ω impedance for better system thermal performance. The CM8.4X is the 4Ω variant of the CM8.2X — same driver, same performance, higher impedance. For dedicated 2Ω-rated amplifiers in stereo, the CM8.2X extracts maximum power.
What This Is Best For
- Active DSP builds with bridged 8-inch mid-bass channels — when channels are bridged for maximum per-channel output, the CM8.4X satisfies the 4Ω minimum load requirement while delivering the same 94 dB output and CMC™ construction from the custom 8-inch position.
- Uniform 4Ω active system builds — for builds where consistent 4Ω impedance across every driver simplifies amplifier matching and reduces total system current demand.
- Full-range single-driver builds at 4Ω — same 70 Hz – 20 kHz full-range capability as the CM8.2X, with the thermal and load benefits of the higher impedance.
- Conservative builds where the amplifier delivers sufficient power at 4Ω — when the amp's 4Ω rated output exceeds 250W per channel, the CM8.4X receives full rated power without requiring the 2Ω operating condition.
2Ω vs 4Ω — Choosing the Right Version
The CM8.4X is a 4Ω mid-bass driver. Choose 4Ω for bridged configurations, conservative system designs, or when the amplifier delivers sufficient power at 4Ω. For maximum output from a dedicated 2Ω-rated amplifier in stereo, the CM8.2X (2Ω) is the correct choice.
The Bottom Line
250W RMS, 94 dB, 8-inch mid-bass component with CMC™ cone and OFC copper shorting ring — full-range capable, the 4Ω version for bridged and conservative custom 8-inch builds.
Ready to build? Add to cart above. For the 2Ω variant, the CM8.2X is the same driver at 2Ω.
What's Inside the CM8.4X
The CM8.4X is identical in construction to the CM8.2X — all construction notes below apply equally to both impedance variants.
The mid-bass cone is Carbon Matrix Composite™ (CMC™) — lightweight, rigid, and thermally stable. The 2.0-inch / 51mm Black Coat™ OFC copper voice coil handles sustained 250W RMS. The OFC copper shorting ring in the motor gap reduces inductance modulation distortion and extends upper-frequency response through 20 kHz — the 4Ω version provides the same full-range performance as the 2Ω variant, with the thermal and load benefits of the higher impedance. On the road: the same mid-bass character and full-range response as the CM8.2X, with the amplifier running cooler on those channels.
The motor is an N35SH neodymium with H-grade temperature rating. The die-cast aluminium basket with Vortex Flow Venting™ manages heat through active airflow. No external crossover is included — designed for direct amplifier drive, with crossover management at the system level if needed.
Sensitivity and Frequency Coverage
At 94 dB (1W/1m) and 250W RMS, the CM8.4X matches the output of the CM8.2X — impedance changes amplifier compatibility, not speaker performance. Frequency response runs 70 Hz – 20 kHz (±3 dB). The 4Ω impedance means the amplifier draws less current on these channels — relevant in multi-speaker builds where total system current demand is a design consideration.
Why 4Ω — Bridged Amps and Thermal Margin
A 4Ω driver presents a higher electrical load than a 2Ω driver — lower current demand, less heat, and compatibility with bridged configurations. For DSP builds where channels are bridged for maximum per-channel output, the 4Ω load satisfies the minimum impedance requirement on amplifiers including the FLX700.4PRO and FLX1400.4PRO. For stereo installs at the amp's rated 2Ω output, the CM8.2X is the matching choice.
Fitment
- Designed for custom 8-inch speaker enclosures — saddlebag lids, Tour-Pak, lower fairing, or bespoke fabricated enclosures. No H-D direct-fit factory position.
- Mounting Depth: 71 mm (2.8 in). Mounting Diameter (cutout): 180 mm (7.1 in).
- No external crossover required — active DSP or external passive crossover at the system level.
- Compatible with 4Ω-rated amplifiers including bridged configurations — FLX700.4PRO, FLX1400.4PRO, and other 4Ω-stable motorcycle amplifiers.
Technical Specifications
| Driver Size | 8 in |
| Driver Type | Mid-bass component (no tweeter) |
| Impedance | 4Ω nominal |
| Power Handling — RMS | 250W RMS |
| Power Handling — MAX | 500W peak |
| Sensitivity | 94 dB (1W/1m) |
| Frequency Response | 70 Hz – 20 kHz (±3 dB) |
| Voice Coil | 2.0 in (51 mm) — Black Coat™ OFC copper |
| Shorting Ring | OFC copper — inductance reduction, distortion control |
| Magnet Type | Neodymium N35SH |
| Cone Material | Carbon Matrix Composite™ (CMC™) |
| Basket | Die-cast aluminium — Vortex Flow Venting™ |
| Crossover | None — active DSP or external passive crossover at system level |
| Mounting Depth | 71 mm (2.8 in) |
| Mounting Diameter (Cutout) | 180 mm (7.1 in) |
| Weather Resistance | Rain or Shine™ — CMC™ cone, OFC shorting ring, Vortex Flow Venting™ |
| Warranty | 2 years |
| Sold As | Pair |
Australia Shipping:
- Under $500 → $19.95
- $500–$2,500 → $14.95
- Over $2,500 → FREE
- Bulky items → +$24.95 surcharge (waived over $2,500)
Fast dispatch from Brisbane. Same-day shipping on in-stock orders before 1pm AEST.
Change-of-mind returns: We accept returns within 7 days of delivery on unused, unopened products in original sealed packaging. Restocking fees apply (20–30%). Return shipping is the customer's responsibility.
No returns on opened audio gear, installed items, custom orders, or special-order products. Please check fitment carefully before installing.
Faulty or incorrect items: If you experience an issue, contact us with photos/video and your order number. We'll assess the claim and arrange repair, replacement, or refund for verified faults under the Australian Consumer Law.
Fitment assistance: If you're unsure about compatibility, reach out before ordering—we're happy to help.