SoundQubed S4-100 S Series 4 Channel Amplifier (175x4)

SoundQubed S4-100 — 4-Channel Amplifier | S-Series | Class D | 175W x 4 @ 2Ω The SoundQubed S4-100 is a high-efficiency Class D 4-channel amplifier built for enthusiasts who want clean, versatile power for their full car audio system. Delivering 100W x 4 at 4Ω, 175W x 4 at 2Ω, and 370W x 2 bridged at 4Ω, the S4-100 balances deep, loud low-end with power for mids and highs — all from a remarkably compact 7.87" x 7.75" x 2.24" chassis. Whether you’re powering a full set of component speakers, running a dedicated mid-range and tweeter setup, or bridging channels for more power to select speakers, the S4-100 has the flexibility to do it all. The S4-100 features a comprehensive crossover suite: a high-pass filter to direct precisely tuned tones to your tweeters and midrange speakers, a low-pass filter (50 Hz–5 kHz) for controlling low-frequency content, and a bandpass filter for defining both the high and low ends of your mid-range speaker tone. Input sensitivity runs from 0.2V to 8V for compatibility with virtually any head unit or DSP. Power connections use 4-gauge set screw terminals for clean current flow, and 10-gauge speaker terminals ensure consistent voltage delivery to your speakers. Operating across a 12V–15.8V working voltage range with a maximum amperage draw of 75A, the S4-100 is compatible with most stock electrical systems. With a frequency response of 10 Hz–40 kHz, a signal-to-noise ratio greater than 80 dB, and a damping factor greater than 100, the S4-100 delivers clean, accurate sound reproduction across all four channels. It’s the perfect foundation for a full front stage build — or a complete system when paired with a dedicated subwoofer amplifier. Why Choose the SoundQubed S4-100? 100W x 4 @ 4Ω / 175W x 4 @ 2Ω / 370W x 2 Bridged @ 4Ω — Flexible power configurations for full-system builds, component setups, and bridged applications. Class D Efficiency — High-efficiency design minimizes heat and maximizes power delivery — runs cool even in compact installs. HPF + LPF + Bandpass Crossover Suite — Full crossover flexibility for precise frequency control across all four channels without a separate DSP. Ultra-Compact 7.87" x 7.75" x 2.24" Chassis — One of the smallest 4-channel amplifiers available — fits under seats, in doors, and in tight custom installs. 4GA Power Terminals + 10GA Speaker Terminals — Clean current flow and consistent voltage delivery for reliable daily performance. 10 Hz–40 kHz Frequency Response — Full-range reproduction from deep sub-bass to extended high frequencies. 12V–15.8V Working Voltage / 75A Max Draw — Compatible with most stock electrical systems — no major electrical upgrades required for most builds. 2Ω Stereo / 4Ω Bridged Stable — Flexible impedance compatibility for a wide range of speaker configurations. System Configuration Recommendations Full Front Stage Build: Run all four channels at 2Ω for 175W per channel to a full set of component speakers. Use the HPF to protect your tweeters and midrange speakers from low-frequency content. The bandpass filter is ideal for separating mid-range speaker tone from your tweeters in a 3-way component setup. Front Stage + Subwoofer: Use channels 1/2 for front component speakers (HPF filtered) and bridge channels 3/4 for a subwoofer or mid-bass driver (LPF filtered) for 370W. Pair with a dedicated SoundQubed S1-850.1 or S1-1250 monoblock for a complete, well-matched system. Electrical Requirements: The S4-100 draws a maximum of 75A and operates from 12V–15.8V, making it compatible with most stock electrical systems. A standard 4-gauge wiring kit is all you need for clean, reliable performance at full output. Full Specifications Specification S4-100 Amplifier Class Class D Channels 4 Working Voltage 12V – 15.8V Maximum Amperage 75A RMS Power @ 4 Ohm — 4-Channel 100W x 4 RMS Power @ 2 Ohm — 4-Channel 175W x 4 RMS Power @ 4 Ohm — Bridged (2-Channel) 370W x 2 Frequency Response 10 Hz – 40 kHz Signal to Noise Ratio >80 dB Damping Factor >100 Input Sensitivity 0.2V – 8V High-Pass Filter 20 Hz – 5 kHz Low-Pass Filter 50 Hz – 5 kHz Bandpass Filter Yes Minimum Impedance (Stereo) 2 Ohm Minimum Impedance (Bridged) 4 Ohm Power Terminal Size 4 Gauge (Set Screw) Speaker Terminal Size 10 Gauge (Set Screw) Overall Length 7.87" Overall Width 7.75" Overall Height 2.24" Frequently Asked Questions Q: Can the S4-100 power my whole car audio system? A: Yes — use channels 1/2 for front speakers (HPF filtered) and bridge channels 3/4 for a mid-bass driver or subwoofer (LPF filtered). For a complete system with dedicated sub bass, pair it with a SoundQubed S1-850.1 or S1-1250 monoblock. Q: What’s the minimum impedance for bridged mode? A: The S4-100 is stable at 4Ω in bridged mode and 2Ω in stereo mode. Do not bridge into a load below 4Ω. Q: Will the S4-100 work with my stock electrical system? A: Yes — the S4-100 draws a maximum of 75A and operates from 12V–15.8V, making it compatible with most stock electrical systems. A standard 4-gauge wiring kit is all you need. Q: What speakers pair best with the S4-100? A: Any component or coaxial speakers rated between 75–175W RMS are a great match. SoundQubed’s mid-range speakers and tweeters are purpose-built to pair with the S-Series amplifier lineup for maximum sound quality and volume.