Ruthless Audio 800.4 Micro 4 Channel Amplifier
Want a stronger four-channel speaker stage without dedicating the whole trunk to an amp? The Ruthless Audio 800.4 Micro 4-Channel Amplifier provides a listed 800W total RMS in a chassis only 9.25" long. It offers room to power front and rear speakers, build a component setup, or use bridged channels when the speakers and load are a proper match. Its compact footprint makes it especially useful when mounting space is limited.
This Class-D amplifier is rated at 200W x 4 @ 2 ohms and 120W x 4 @ 4 ohms at 14.4V. A listed 95dB signal-to-noise ratio and adjustable high-pass (20Hz–8kHz) and low-pass (50Hz–8kHz) filters give you specifications and controls to consider when designing your system. The listed fuse rating is 80A and operating range is 9–16V; size the wiring and confirm the vehicle's electrical supply for the actual installation.
At 9.25" overall length, with an 8.25" heatsink, 4.7" width, and 2.2" height, this amp can fit where a larger chassis may not. Use all four channels for separate speaker runs or bridge channels 1+2 and 3+4 into two channels at the specified minimum load. Whether tucked under a seat or mounted in a custom space, leave enough access for wiring and ventilation.
Why Choose the Ruthless Audio 800.4 Micro Amplifier?
- 800W Total RMS Rating — Four channels rated at 200W each into 2Ω at 14.4V.
- Compact Micro Chassis — A 9.25" overall length offers more options for tight installations.
- Class-D Design — A compact amplifier topology suited to space-conscious systems.
- Bridgeable Four-Channel Layout — Run four speakers independently or bridge channel pairs for a two-channel configuration with suitable loads.
- High-Pass & Low-Pass Filters — Listed adjustment ranges are 20Hz–8kHz HPF and 50Hz–8kHz LPF.
- 95dB Signal-to-Noise Rating — A published measurement to compare with your system goals.
- 9–16V Operating Range — Check your vehicle's supply against the amplifier's stated range.
- Installation Flexibility — A 4.7" width and 2.2" height help with under-seat and custom placement, subject to airflow and clearance.
Amplifier & Wiring Recommendations
Consider the 800.4 for component or coaxial speakers with suitable impedance and RMS handling in the 100–200W-per-channel range. Feed it a compatible four-channel RCA signal from a head unit or DSP. A 4-gauge power and ground kit is recommended in the original listing for its 80A fuse rating; confirm the cable and protection sizes for the actual run. When bridging, verify speaker power handling and keep the load at a minimum of 4Ω per bridged pair.
Keep power and ground runs appropriately sized and secured, and separate RCA routing from power wiring when possible to reduce noise. For an under-seat or enclosed mount, check fit and provide approximately 1–2" of clearance around the heatsink for airflow. Protect connections from moisture if the installation is on a motorcycle or powersports vehicle; compact does not automatically mean weatherproof.
Full Specifications
| Specification | Value |
|---|---|
| RMS Power (2Ω) | 200W x 4 @ 14.4V |
| RMS Power (4Ω) | 120W x 4 @ 14.4V |
| Total RMS Power | 800W |
| 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 | 80A |
| Operating Voltage | 9–16V |
| Overall Length | 9.25" |
| Heatsink Length | 8.25" |
| Width | 4.7" |
| Height | 2.2" |
| Warranty | 1 Year Standard / 2 Year Extended Available |
Frequently Asked Questions
Q: What size wiring kit do I need for the Ruthless Audio 800.4?
A: The original listing recommends a 4-gauge power and ground kit for the 80A fuse rating. Confirm wiring and protective fusing based on your cable length and installation.
Q: Can I bridge the 800.4 down to 2 channels?
A: Yes. Bridge channels 1+2 and 3+4 for two higher-output channels, using speakers suited to the bridged output and a minimum 4Ω load per pair.
Q: How does the 800.4 compare to the Ruthless Audio 400.4?
A: At 2Ω and 14.4V, the listed four-channel ratings are 200W x 4 for the 800.4 versus 100W x 4 for the 400.4. The 800.4 is longer at 9.25" versus 7.25", so compare both power needs and available mounting space.
Q: Is the 800.4 suitable for motorcycle or powersports installs?
A: Its compact dimensions make it an option to consider where space is limited. Check electrical capacity, secure mounting, ventilation, and protection from weather before choosing that location.
