Nakamichi NBF25.5A 9.2 Inch Active Subwoofer with Built-In 150W Amplifier and Stinger STK8 8 Gauge Amplifier Wiring Kit Bundle

Nakamichi NBF25.5A 9.2 Inch Active Subwoofer with Built-In 150W Amplifier and Stinger STK8 8 Gauge Amplifier Wiring Kit Bundle

Complete plug-and-play bass upgrade bundle combining the Nakamichi NBF25.5A 9.2-inch active subwoofer with built-in 150W amplifier and the Stinger STK8 8-gauge 2-channel amplifier wiring kit, providing everything needed to install a powered subwoofer system in your vehicle.

Product Overview

The NBF25.5A-STK8 bundle pairs two complementary products for a complete, ready-to-install powered subwoofer solution. No hunting for wiring separately as this bundle includes everything from the subwoofer unit itself to the power cable, RCA leads, fuse holder, and installation accessories.

Nakamichi NBF25.5A Active Subwoofer

The Nakamichi NBF25.5A is a professional-grade active subwoofer system combining a 9.2-inch aluminum cone driver with a built-in 150W N-Power amplifier in an ultra-compact enclosure just 71mm tall. The aluminum cone delivers rigid, accurate bass reproduction with ultra-low distortion (0.2% THD) and an extended frequency response from 20Hz to 150Hz. The integrated amplifier includes an adjustable low-pass filter (50Hz-150Hz), variable bass boost (0-12dB), and a fixed 20Hz subsonic filter for complete tuning control. Both high-level and low-level RCA inputs allow connection to factory or aftermarket head units without a signal processor.

At 300mm x 235mm x 71mm, the NBF25.5A fits under seats, behind seats, or in tight boot spaces where traditional subwoofer enclosures cannot.

Stinger STK8 8 Gauge Amplifier Wiring Kit

The Stinger STK8 is a complete 8-gauge amplifier wiring kit providing all essential installation hardware for the NBF25.5A. The kit includes 8-gauge power and earth wire, a 5-metre RCA cable, 5-metre trigger wire, 6-metre 16-gauge speaker wire, a mini ANL fuse holder with 60A fuse, and all necessary installation accessories for a clean, complete wiring installation.

Features & Benefits

Complete Bundle — Subwoofer Plus Wiring Combines the powered subwoofer and all required wiring hardware in one purchase, eliminating the need to source installation components separately.

Built-In 150W Amplifier The NBF25.5A's integrated N-Power amplifier delivers 150W RMS (1500W peak) without requiring an external amplifier, reducing installation complexity and cost.

9.2-Inch Aluminum Cone Driver Lightweight and rigid aluminum cone construction delivers accurate, distortion-free bass with excellent transient response and ultra-low 0.2% THD.

Ultra-Compact 71mm Profile At just 71mm tall, the NBF25.5A fits under seats, behind seats, or in tight spaces where traditional subwoofer boxes cannot be installed.

Adjustable Tuning Controls Adjustable low-pass filter (50Hz-150Hz), variable bass boost (0-12dB), and fixed 20Hz subsonic filter provide comprehensive tuning flexibility to suit any vehicle and musical preference.

High and Low Level Inputs Dual input options (high-level 0.5V and low-level 110mV RCA) allow connection directly to factory head units or aftermarket receivers without additional signal adapters.

Stinger 8-Gauge Wiring Kit Included The STK8 provides 8-gauge power and earth wire, 5m RCA cable, 5m trigger wire, 6m 16-gauge speaker wire, mini ANL fuse holder with 60A fuse, and installation accessories for a complete, clean installation.

20A Fuse Protection Integrated 20A fuse protects the NBF25.5A amplifier circuitry and vehicle electrical system from short circuits and overload.

Technical Specs

Nakamichi NBF25.5A Active Subwoofer

Stinger STK8 Amplifier Wiring Kit

Compatible With / Goes Well With

The NBF25.5A-STK8 bundle is a universal active subwoofer and wiring solution compatible with any vehicle featuring a factory or aftermarket head unit with high-level or RCA outputs.

Goes Well With:

• Aftermarket head unit with RCA preamp outputs
• Factory steering wheel control interface
• Aftermarket front stage speakers and amplifier
• Sound deadening for improved bass performance

Frequently Asked Questions

Does this bundle include everything I need to install the subwoofer?

Yes. The NBF25.5A-STK8 bundle includes the Nakamichi NBF25.5A active powered subwoofer and the Stinger STK8 8-gauge wiring kit with power wire, earth wire, RCA cable, trigger wire, speaker wire, fuse holder, and installation accessories. No external amplifier is required as the NBF25.5A has a built-in 150W amplifier. Professional installation is recommended to ensure correct power, ground, and signal connections.

Can I connect the NBF25.5A directly to my factory head unit?

Yes. The NBF25.5A supports both high-level inputs (0.5V sensitivity) and low-level RCA inputs (110mV sensitivity), allowing direct connection to factory head units via speaker-level outputs or to aftermarket head units via RCA preamp outputs. No additional signal adapter or line output converter is required for most factory radio installations.

Will the NBF25.5A fit under the seat of my vehicle?

The NBF25.5A measures 300mm x 235mm x 71mm with a 71mm (2.8 inch) height profile. This ultra-slim dimension makes it compatible with most under-seat and behind-seat spaces in passenger cars, SUVs, and utes. Measure your available space before purchasing to confirm fitment in your specific vehicle.

How do I set the low-pass filter and bass boost on the NBF25.5A?

The low-pass filter is adjustable between 50Hz and 150Hz, allowing you to set the crossover point to blend the subwoofer seamlessly with your front stage speakers. The bass boost is variable between 0 and 12dB, allowing you to increase low-frequency output to suit your vehicle acoustics and personal preference. The fixed 20Hz subsonic filter engages automatically and cannot be adjusted. We recommend setting these controls with the system playing to dial in the best result for your vehicle.

Is professional installation required for this bundle?

While this bundle includes all required wiring hardware, we strongly recommend professional installation by a qualified car audio installer. Correct power and ground connections, appropriate cable routing, and proper amplifier tuning are essential for safe, reliable operation and optimal sound quality.