Ruthless Audio 400.4 Micro 4 Channel Amplifier
Key features
- Amplifier channels: 4
- RMS per channel at 4 ohms: 60 W
- RMS per channel at 2 ohms: 100 W
- Amplifier class: D
- High-pass filter: 20 Hz–8 kHz
- Low-pass filter: 50 Hz–8 kHz
Ruthless Audio 400.4 Micro 4 Channel Amplifier - No is backordered and will ship as soon as it is back in stock.
Ruthless Audio 400.4 Micro 4 Channel Amplifier - No is backordered and will ship as soon as it is back in stock.
Description
Description
Product Overview
Add four-channel power to a space-conscious audio system with the Ruthless Audio 400.4 Micro 4 Channel Amplifier. This Class-D car audio amplifier delivers up to 100W x 4 at 2 ohms and measures just 7.25 inches long.
Use all four channels for front and rear speakers, or bridge channel pairs for a two-channel setup. Its compact dimensions make it an option for tight custom installs, including motorcycle and powersports systems.
Key Features & Benefits
- Four-channel output: Run a front and rear speaker stage from one amplifier.
- Bridgeable design: Combine channels in pairs for a two-channel configuration.
- Onboard filters: High-pass and low-pass controls let you set crossover points without an external processor.
- Compact footprint: The 7.25-inch length, 4.7-inch width, and 2.2-inch height suit installs with limited space.
- Class-D circuitry: The high-efficiency design helps limit heat while delivering power.
- 95dB signal-to-noise ratio: This rating supports a quieter background for music playback.
Technical Specifications
| Specification | Value |
|---|---|
| RMS Power (2Ω) | 100W x 4 @ 14.4V |
| RMS Power (4Ω) | 60W x 4 @ 14.4V |
| Total RMS Power | 400W |
| Amplifier Class | Class-D |
| Channels | 4 (Bridgeable to 2) |
| Frequency Response | 20Hz – 8kHz |
| High Pass Filter | 20Hz – 8kHz |
| Low Pass Filter | 50Hz – 8kHz |
| Signal-to-Noise Ratio | 95dB |
| Fuse Rating | 60A |
| Operating Voltage | 9–16V |
| Overall Length | 7.25" |
| Heatsink Length | 6.375" |
| Width | 4.7" |
| Height | 2.2" |
| Warranty | 1 Year Standard / 2 Year Extended Available |
Why Choose This Product?
The 400.4 combines four-channel flexibility with a small chassis, helping you plan an audio upgrade when amplifier space is limited. Its power ratings support selecting speakers in the recommended 60–100W RMS range per channel.
Use the onboard filters to shape the system’s crossover points, or bridge channels in pairs when planning a two-channel setup. The 9–16V operating range accommodates a range of vehicle electrical systems.
Installation & Compatibility Notes
A 4-gauge power and ground wiring kit is recommended for the 60A fuse rating. Keep power and ground runs short, and route RCA cables away from power wiring to help reduce noise.
When bridging, confirm that the speakers are rated for a minimum 4-ohm bridged load and can handle the increased output. For enclosed installs, allow 1–2 inches of airflow clearance around the amplifier. In motorcycle or powersports installations, weatherproof connections and secure the amplifier to a vibration-dampened surface.
Frequently Asked Questions
How much power does the Ruthless Audio 400.4 produce?
It is rated at 100W x 4 at 2 ohms and 60W x 4 at 4 ohms, both at 14.4V. Total RMS power is 400W.
Can I bridge this four-channel amplifier?
Yes. Bridge channels 1+2 and 3+4 for a two-channel configuration. Speakers must be rated for a minimum 4-ohm bridged load.
What speakers can I pair with the 400.4?
The recommended match is component or coaxial speakers rated at 60–100W RMS per channel. Check each speaker’s impedance and power handling for your chosen setup.
What wiring kit is recommended?
A 4-gauge power and ground wiring kit is recommended to support the amplifier’s 60A fuse rating.
Does the amplifier have crossover controls?
Yes. It has a 20Hz–8kHz high-pass filter and a 50Hz–8kHz low-pass filter.
Explore More
Shop at 12 Volt Outlet for your audio system. Want to learn more about Ruthless Audio? Explore our Ruthless Audio brand profile.
