Rockford Fosgate PBR400X4D - Compact 400W 4-Channel Class-D Amplifier

Overview

The Rockford Fosgate Punch PBR400X4D is a compact yet mighty 400-watt, full-range amplifier designed to fit in tight spaces without sacrificing performance. With its slim footprint (approximately 1.5" x 4.25" x 6.75"), this unit frees up trunk, under-seat, or dash space while delivering solid, dependable power to your four-channel system.

Power, flexibility, and real-world utility

Configure this amp for 2- or 4-channel operation, with power options that adapt to your setup: 50W x 4 @ 4 ohms, 100W x 4 @ 2 ohms, or 200W x 2 when bridged at 4 ohms. This makes it a strong candidate for upgrading factory speakers, adding a dedicated front-stage, or pairing a compact, sub-friendly channel for a balanced dashboard install.

• Four-channel operation supports clean, consistent output across front and rear speakers.
• Bridged mode enables higher power to a single channel pair when needed.

Efficiency you can feel in everyday driving situations

Built on an ultra-efficient Class D design, the PBR400X4D maximizes power output while minimizing stress on your vehicle’s electrical system. The result is capable performance with reduced heat generation—beneficial for mobile installs, motorcycles, or RVs where space and power budgets matter.

• Class D efficiency helps preserve electrical capacity and battery health.
• Compact form and cooler operation support longer listening sessions in mobile setups.

Input versatility and precise sound shaping

High-level inputs with auto-on make integration simple with many head units, while differential RCA inputs offer a balanced signal path. Selectable fixed 12 dB/octave Butterworth crossovers provide straightforward tone shaping, accommodating a wide range of speaker configurations and installation scenarios.

• Auto-on supports seamless startup with various head units.
• Crossovers enable clean crossover points and better channel separation.

Durability and a trusted warranty

Rockford Fosgate is known for durable build quality, and the PBR400X4D reflects that reputation with robust components and reliable switching. A full 1-year parts and labor warranty adds peace of mind for both everyday drivers and seasoned installers.

In practical use, this compact amplifier is ideal for projects where space is at a premium but sound quality remains a priority. It pairs well with compact component sets in cars, motorcycles, or small campers where a capable, efficient amplifier can unlock noticeably improved audio performance without crowding the install space.