Sundown Audio SDX-400.1 Weatherproof Mono Amplifier
Many in-stock orders ship within 1-2 business days, but timing varies by item. Custom, built-to-order, oversized, special-order and supplier-direct products may need extra processing time. Free shipping applies to qualifying orders over $99 in the contiguous US. Approved returns may be subject to a restocking fee.
Most products are covered by the manufacturer's warranty against defects. Damage from over-powering or improper installation isn't covered — we'll help coordinate any valid claim.
Tell us your vehicle, subwoofers and electrical setup and our team will help you match the right gear. Reach out before you buy.
Subwoofer Wiring Diagram
Select your configuration to view possible wiring combinations.
Loading wiring diagrams…
Diagrams are on our wiring diagram page.
- RMS Power — 400W x 1 @ 1Ω, 300W x 1 @ 2Ω, 175W x 1 @ 4Ω
- Class — Class D monoblock
- Low-Pass Filter — Variable 12dB, 50Hz–250Hz
- Bass Boost — Variable 12dB
- Weatherproofing — Water-resistant with removable sealed audio control cover
This Listing Includes: (1) Sundown Audio SDX-400.1 Weatherproof Mono Amplifier
The SDX-400.1 is a compact water-resistant Class D monoblock rated at 400 watts at 1 ohm, 300 watts at 2 ohms, and 175 watts at 4 ohms. It features a variable 12dB low-pass filter from 50Hz to 250Hz, a variable 12dB bass boost, and DC auto-sensing turn-on, with a full suite of audio controls protected beneath a removable sealed cover. A heavy cast aluminum heat sink provides superior heat dissipation and shields the amp from the elements, and thermal, voltage, speaker-short, and DC-offset protection circuitry guards the unit. Built for cars, UTVs, and open-air vehicles, it ships with a wired remote control. Authorized Sundown Audio dealer at JS Ultimate Sounds. Free shipping on orders $99+.
Features
- Water-resistant design for powersports and daily drivers
- Heavy cast aluminum heat sink for superior cooling
- Removable sealed audio control cover (badge unscrews with an allen key)
- DC auto-sensing turn-on
- Wired remote control included
Specifications
| RMS @ 1Ω | 400W x 1 |
| RMS @ 2Ω | 300W x 1 |
| RMS @ 4Ω | 175W x 1 |
| Low-Pass Filter | Variable 12dB, 50Hz–250Hz |
| Bass Boost | Variable 12dB |
| Turn-On | DC auto-sensing |
| Protection | Thermal, voltage, speaker short, DC-offset |
