Stetsom HL400.4 4-Channel DSP Car Amplifier

Four-channel car audio with built-in DSP and media playback

The Stetsom HL400.4 is listed as a four-channel car amplifier with a built-in media player and digital signal processing. Inputs include RCA, high-level, optical, USB, Bluetooth and FM; two DSP RCA outputs are also listed. Before choosing speakers or bridging channels, check the official manual for impedance, power, wiring and installation requirements.

Power ratings listed at 14.4 V

• Stereo, 2 Ω per channel: 4 × 105 W RMS.
• Stereo, 4 Ω per channel: 4 × 70 W RMS.
• Bridged, 4 Ω per bridge: 2 × 210 W RMS.
• Minimum output impedance listed: 2 Ω per stereo channel or 4 Ω per bridged pair.

Connections and features listed

• Inputs: RCA, high-level wire, optical SPDIF, USB, Bluetooth and FM radio.
• Outputs: four amplified channels and two DSP RCA outputs.
• DSP controls listed through the app: equalizer, crossover, phase, delay, balance and level.
• USB playback: MP3 from FAT32 devices up to 64 GB, as stated by the seller.
• Frequency response: 20 Hz–20 kHz at -3 dB.
• Signal-to-noise ratio: 90 dB.
• Operating supply voltage: 9–15 V DC.
• Remote output: maximum 200 mA.
• Consumption stated at 12.6 V: 16.5 A for music and 33 A in bass mode.
• Dimensions: 50 × 125 × 139 mm (measurement order not specified in the source).
• Listed product weight: 0.5 kg; packed shipping weight was not provided.

The source describes compatibility with a separately sold Stetsom long-range remote control. Confirm the exact compatible model and whether it is included before purchase. Follow the manufacturer's wiring and fuse instructions; get a qualified installer to verify speaker impedance, power supply and setup.