Alpine S2-A120M Amplifier 1 Channel Class D Monoblock Subwoofer Car Amp 1200w
Couldn't Load Pickup availability
The Alpine S2-A120M is a Class D monoblock subwoofer amplifier from Alpine's S2-Series, delivering 1200W RMS at 1 or 2 ohms (600W at 4 ohms). It includes speaker-level inputs with automatic turn-on, a variable low-pass filter, and bass EQ, making it straightforward to integrate with factory or aftermarket systems.
Key specifications
- Channels: 1 (mono), Class D
- RMS power: 1 x 1200W at 1 ohm and 2 ohms, 1 x 600W at 4 ohms (14.4V)
- Crossover: variable LPF 50–400Hz (-24dB/oct)
- Bass EQ: up to +12dB
- Inputs: RCA and speaker level with automatic power on
- Turn-on modes: DC HI, Remote HI, Remote LO
- Remote: RUX-KNOB2 compatible
- Weight: 4.0kg
- Heat sink (W x H x D): 352 x 57 x 210mm
Alpine S2-Series mono subwoofer amplifier
The S2-A120M is part of Alpine's next-generation S-Series amplifier range — a redesigned and upgraded line aimed at delivering strong performance on an accessible budget. With 1200W RMS at 2 ohms, it can drive multiple subwoofers from a single amp. A variable bass boost lets you dial in extra low-frequency punch, and an optional wired remote lets you adjust bass level from the front seat.
The built-in low-pass filter gives you control over the frequency range sent to your sub. Both RCA pre-amp and speaker-level inputs are included, so it can be fitted to virtually any vehicle, including those with a factory head unit. When using speaker-level inputs, the amp senses the incoming signal and powers itself on automatically — no separate turn-on wire needed.
Power for demanding subwoofers
At 1200W RMS into 1 or 2 ohms, the S2-A120M handles even the most demanding subwoofers, delivering clean, distortion-free bass across a wide range of installations.
Flexible application
A new selectable remote turn-on circuit uses a three-position switch to ensure the amp powers on and off at the correct times. This allows reliable integration with both modern factory systems and aftermarket head units.
Easy control access
Gain and crossover controls are positioned on the side panels rather than the top, making them easier to reach when the amp is mounted under a seat or in a shallow-depth location. Removable end-caps cover the side controls and connections for a clean finish.
Explore the full range in Alpine Amplifiers.
Specification
| Channel Design | Mono Channel |
|---|---|
| Crossover | Variable Low-pass Filter (LPF) |
| Crossover | Variable LPF: 50-400Hz (-24dB/oct) |
| Power Requirements | 14.4 V.DC (9 - 16 V allowable) |
| Input Sensitivity (RCA Input) | Hi: 0.5V - 10V / Low: 0.2V - 4.0V |
| Frequency Response | (+0, -3dB 1W into 4 ohms): 10Hz – 400Hz |
| THD+N (@ 10W into 4 Ohms) | <0.03% |
| Damping Factor | >750 |
| Weight | 4.0kg |
| Heat Sink (WxHxD) mm | 352 x 57 x 210 |
More specs
| |
What's Included
- Alpine S2-A120M Mono subwoofer amplifier (four 25A ATO fuses installed)
- 2 End caps
- Four 3/4" screws
- Four 1/4" screws
- 2mm Allen key
Alpine
About the Alpine S2-A120M
From our tech experts at CEN
A monoblock amplifier built for subwoofer duty, Class D. One channel, all of it going to the bass.
Who it suits
Anyone adding a subwoofer that needs more than a head unit or a compact powered unit can give it. Amplification is also what turns a van or camper system from loud into clear.
Our tech experts advise
Power ratings only mean something when the amplifier is matched to the speakers and the gains are set with a meter rather than by ear. It needs a properly fused feed from the battery on the right gauge cable, which is the part we see done badly most often. Installation is priced per vehicle, so get in touch with your make, model and year and we will confirm what it needs and what the work involves. See car audio installation.
Explore the full Alpine range at CEN, with fast UK dispatch and expert advice from our Nottingham team. Shop all Alpine
Recommended For You
Discover more top-rated gear, handpicked to go with what you're viewing
Alpine News & Guides
The latest Alpine product news, launches and guides from the CEN team in Nottingham.
Alpine iLX-F905D Halo9 Review: The Big-Screen Upgrade for Almost Any Car
The Alpine iLX-F905D Halo9 solves the biggest problem in car stereo upgrades: wanting a big screen in a car with...
Looking for Installation?
At CEN we take pride in being able to share the quality of our work as well as being able to show what incredible products we have installed week on week.
More from Alpine Amplifiers
More options from the same range, in stock and ready to go
Save 22% Alpine S2-A60M Amplifier 1 Channel Class D Monoblock Subwoofer Car Amp 600w RMS RRP£329.99£259.00 / Save 22%Low stock
Save 9% Alpine S2-A36F Amplifier 4 Channel Class D Bridgeable Stereo Car Amp 360w RMS RRP£329.99£299.00 / Save 9%Low stock
Alpine SWA-150KIT Amp 2 Channel Amplifier with Bass Remote Designed for SWC-D84S £129.99 /Low stock
Frequently Asked Questions
Q: How do I choose the right amplifier for my speakers or subwoofer?
A: Match the amplifier's RMS output per channel to the RMS handling of your speakers or subwoofer at the same impedance. The Specification tab lists the power figures. If in doubt, contact CEN with your setup and we will recommend a match.
Q: What wiring do I need to install this amplifier?
A: You will need an amplifier wiring kit sized to the amplifier's power draw, typically including power and earth cable, a fuse, RCA leads and a remote wire. CEN stocks complete wiring kits, and the amplifier's fuse rating is the guide to the cable gauge required.
Q: What class of amplifier is this and does it matter?
A: Class D amplifiers are compact and efficient, ideal for subwoofers and modern installs. Class AB designs are traditionally favoured for outright sound quality on mid and high frequencies. The class is listed in the Specification tab where provided.
Q: Will an amplifier work with my factory head unit?
A: Yes, in most cases. If your head unit has no RCA outputs you will need a line output converter to feed the amplifier a clean signal. CEN stocks line output converters and can advise the right one for your vehicle.
Q: Can CEN install this amplifier?
A: Yes. CEN offers professional amplifier installation from our Nottingham premises, including secure mounting, wiring and setup. Contact us to book.
Q: How much power does the Alpine S2-A120M deliver?
A: It delivers 1 x 1200W RMS at 1 ohm or 2 ohms and 1 x 600W RMS at 4 ohms, measured at 14.4V.
Q: Can the S2-A120M connect to a factory head unit?
A: Yes. It has speaker-level inputs with automatic power on, as well as RCA inputs, and a selectable turn-on circuit (DC HI, Remote HI, Remote LO).
Q: Can I control the bass level of the S2-A120M from the front seat?
A: Yes. It is ready for the optional Alpine RUX-KNOB2 wired remote bass control.
