SoundQubed S1-1250 S Series Monoblock Amplifier
Description
Description
SoundQubed S1-1250 — 1,260W Mono Amplifier | S-Series | Class D | 1 Ohm Stable
The SoundQubed S1-1250 is a compact, efficient Class D monoblock amplifier delivering 1,260W RMS at 1 ohm (14.4V) — and pushing close to 1,500W at 16V — in a chassis that measures just 11.8" x 7.8" x 2.2". Part of SoundQubed’s S-Series lineup, the S1-1250 is engineered for enthusiasts who want real, reliable bass without overbuilding their system. It’s the perfect match for a pair of HDS2.2 Series subwoofers or a single HDS3.1 or HDS3.2 — with headroom to spare for daily listening and weekend demos alike.
The S1-1250 features an on-board low-pass filter (20–200 Hz) for precise frequency control, a subsonic filter (10–50 Hz) to protect your drivers from extreme low-resonance distortion, and a clipping indicator on the bass knob so you always know exactly where your gain is set. Input sensitivity runs from 0.15V to 5V 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 subwoofer. And when you’re ready to go bigger — the S1-1250 is strappable, so you can link two units for even more output.
Operating across a wide 8.5V–16V working voltage range, the S1-1250 is a versatile, dependable daily driver amplifier that delivers real bass performance at a price point that makes sense. Save money, get more bass.
Why Choose the SoundQubed S1-1250?
- 1,260W RMS @ 1 Ohm (14.4V) / ~1,500W @ 16V — Serious output for a compact S-Series monoblock — more than enough for most daily driver subwoofer builds.
- Class D Efficiency — High-efficiency design minimizes heat and maximizes power delivery to your subwoofers.
- Strappable — Link two S1-1250 units for even more output when your build demands it.
- Clipping Indicator on Bass Knob — Know exactly where your gain is set and avoid distortion — a feature that protects your subwoofers and your ears.
- Variable LPF (20–200 Hz) + Subsonic Filter (10–50 Hz) — Precise crossover and subsonic control for optimal tuning and driver protection.
- 4GA Power Terminals + 10GA Speaker Terminals — Clean current flow and consistent voltage delivery for reliable daily performance.
- 8.5V–16V Working Voltage Range — Compatible with stock and upgraded electrical systems alike.
- Compact 11.8" x 7.8" x 2.2" Chassis — Fits virtually anywhere — trunk, under seat, or custom enclosure builds.
Amplifier & Subwoofer Recommendations
Subwoofer Pairing: The S1-1250 is an ideal match for SoundQubed’s HDS2.2 Series subwoofers — run two wired to a 1Ω final load for a perfectly matched system. It also drives a single HDS3.1 or HDS3.2 with headroom to spare. Use the variable low-pass filter to set your crossover point between 50–80 Hz for most ported builds, and engage the subsonic filter to protect your drivers below their tuning frequency.
Electrical Requirements: The S1-1250 is compatible with stock electrical systems for most builds. For maximum output at 16V, a high-output alternator and upgraded battery are recommended. Proper 4-gauge power and ground wiring is required for clean, reliable performance.
Full Specifications
| Specification | S1-1250 |
|---|---|
| Amplifier Class | Class D |
| Channels | 1 |
| Working Voltage | 8.5V – 16V |
| RMS Power @ 4 Ohm (14.4V) | 530W |
| RMS Power @ 2 Ohm (14.4V) | 860W |
| RMS Power @ 1 Ohm (14.4V) | 1,260W |
| Frequency Response | 10 Hz – 200 Hz |
| Signal to Noise Ratio | >80 dB |
| Damping Factor | >100 |
| Input Sensitivity | 0.15V – 5V |
| Subsonic Filter | 10 Hz – 50 Hz |
| Low-Pass Filter | 20 Hz – 200 Hz |
| Power Terminal Size | 4 Gauge (Set Screw) |
| Speaker Terminal Size | 10 Gauge |
| Clipping Indicator | Yes (on Bass Knob) |
| Strappable | Yes |
| Overall Length | 11.8" |
| Overall Width | 7.8" |
| Overall Height | 2.2" |
Frequently Asked Questions
Q: What subwoofers pair best with the S1-1250?
A: The S1-1250 is a perfect match for two SoundQubed HDS2.2 Series subwoofers wired to 1Ω, or a single HDS3.1 or HDS3.2 with headroom to spare. It’s also a great entry-level amp for any subwoofer rated between 500–1,200W RMS.
Q: Can I strap two S1-1250 amplifiers together?
A: Yes — the S1-1250 is strappable, allowing you to link two units for significantly more output when your build demands it. This is a great upgrade path if you start with one amp and want to grow your system later.
Q: What does the clipping indicator do?
A: The clipping indicator on the bass knob lights up when the amplifier is being pushed into clipping (distortion). This lets you set your gain correctly and protect your subwoofers from distortion damage — an invaluable feature for daily driver builds.
Q: Will the S1-1250 work with my stock electrical system?
A: Yes — the S1-1250 operates from 8.5V to 16V and is compatible with most stock electrical systems for everyday listening. For maximum output near 1,500W at 16V, a high-output alternator and upgraded battery are recommended.
