◆ AC Series · Class-D Monoblock · 2026 Edition
AC1800KD1
Compact Class-D Monoblock Amplifier
$569.99
● Out of Stock
Free shipping over $99
RMS Power1800W @ 1Ω
Impedance1-Ohm Stable
Freq. Response10Hz – 250Hz
PCB4-Layer SMD
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◆ AC Series · Class-D Monoblock · 2026 Edition
Compact Class-D Monoblock Amplifier

AC1800KD1

Compact. 1,800 watts of independently verified RMS power. Not peak. Not rated at conditions you'll never see. What's on the spec sheet is what comes out of the terminals — every time.

1800W
RMS @ 1Ω
1200W
RMS @ 2Ω
650W
RMS @ 4Ω
BassKnob
Included
Lab-Verified Power. Every Build. No Inflated Peak Numbers. Ever.
Every Aunex amplifier is independently tested at rated power. What's on the box is what comes out of the terminals.
Power Output · RMS · Verified @ 14.4V DC
AC1800KD1
Digital Monoblock
1 OHM
1800 W RMS
2 OHM
1200 W RMS
4 OHM
650 W RMS
The Aunex Standard

Compact.
Class-D.
Uncompromised.

The car audio industry has a power inflation problem. Most amplifiers on shelves today are marketed with numbers measured under ideal lab conditions — optimistic test frequencies, burst measurements, and load tolerances that no real install will ever replicate. The result is a watt figure that looks impressive on a box and disappears the moment you turn the key.

We built the AC1800KD1 to end that conversation. Every unit is independently tested at rated power under real-world operating conditions. 1,800W RMS at 1 ohm — measurable, repeatable, and printed on the box without an asterisk. This is the amplifier for anyone who has ever been burned by inflated specs.

"What's on the box is what comes out of the terminals — no inflated peak numbers, ever."

— The Aunex Power Promise
Technical Specifications

Everything You Need.
Nothing You Don't.

Class / Topology
Class-D Monoblock
Rated Power @ 1Ω RMS
1800W
Rated Power @ 2Ω RMS
1200W
Rated Power @ 4Ω RMS
650W
Impedance Stability
1-Ohm Mono Stable
Frequency Response
10Hz – 250Hz ±2.5dB
Signal-to-Noise Ratio
>94 dB
THD + Noise
<1.0%
Low-Pass Crossover
50Hz – 250Hz (Variable)
Crossover Slope
24dB/Octave
Subsonic Filter
10Hz – 50Hz
Bass Boost
0 – 18dB @ 45Hz
Phase Shift
0° / 180°
Input Sensitivity
400mV – 20V
Operating Voltage
9 – 17V DC
PCB Construction
4-Layer SMD Technology
Heatsink
Custom Anodized Extruded
Dimensions (W×H×L)
5.70 × 2.02 × 11.43"
144.92 × 51.2 × 290.4 mm
Engineering Details

Built for the
Real World.

The AC1800KD1 is engineered for vehicles that move through vibration, heat spikes, and electrical noise every single day. We over-engineered every layer because a component that fails on the road isn't just inconvenient — it's a promise we broke. Every feature below is here for a reason.

4-Layer PCB

4-Layer PCB · SMD Technology

Unlike the 2-layer boards standard at this price point, the AC1800KD1's custom 4-layer PCB incorporates dedicated internal power and ground planes. Those buried copper layers act as a Faraday shield — eliminating alternator whine and EMI at the source, not masking it downstream. The added copper mass also increases structural rigidity and thermal dissipation, so the board runs cooler under sustained load and survives the road vibration that eventually fractures solder joints in lesser builds.

Zero-Point

Zero-Point Balanced Inputs (CMRR)

These inputs utilize a fully balanced architecture paired with premium, chassis-mounted Tiffany-style RCAs to provide a superior mechanical connection and maximum signal integrity. By leveraging high CMRR (Common-Mode Rejection Ratio) technology, the system actively neutralizes electrical noise at the entry point, ensuring a "zero-point" baseline for pure audio. This professional-grade stage offers ultimate flexibility, integrating seamlessly with high-end processors or OEM source units while maintaining a dead-silent noise floor.

Visual Clipping

Real-Time LED Visual Clipping Indicator

Visual feedback at a glance. The integrated LED clipping indicator gives you instant confirmation that you're maximizing output without distorting your sub — a feature typically reserved for amplifiers at twice the price point.

Remote Bass

Remote Bass Knob Included

Drive-time bass control, included in the box. Adjust your low-end from the driver's seat without taking your eyes off the road. Most amplifiers at this price point treat it as a paid add-on. With Aunex, it's standard.

4-Way Protection

4-Way Protection Circuitry

Thermal shutdown, short circuit protection, under-voltage and over-voltage protection work in concert to protect both the amplifier and your connected subwoofer. We built the safety net in — not as an afterthought.

Spectra-Core

Spectra-Core RGB Illumination · Custom Heatsink

An extruded, custom-anodized aluminum heatsink manages heat with authority and provides a premium aesthetic. Integrated RGB illumination makes the install look as serious as it performs — no additional lighting kits needed.

Solid Nickel

Solid Nickel-Plated Terminals

Copper corrodes. Untreated steel corrodes faster. Nickel doesn't. Our industrial-grade block terminals are solid nickel-plated to maintain a low-resistance connection years after install — not just on day one. Rated for heavy-gauge wire up to 4 AWG on power and ground, 8 AWG on speaker outputs. Every milliohm of contact resistance you eliminate at the terminal is headroom that reaches your subwoofer instead of turning into heat at the connector.

On/Off Delay

Soft On/Off Delay

An intelligent soft-start circuit sequences internal power ramping at turn-on and turn-off, eliminating the thump or pop that travels through your subwoofer every time you start or stop the vehicle. This isn't a cosmetic feature — repeated voltage transients are one of the most common causes of premature voice coil failure. The AC1800KD1 handles the sequencing internally so your sub doesn't absorb the hit.

The Aunex Difference

Every Standard.
Every Unit.

These aren't options, upgrades, or premium-tier exclusives. Every feature listed below ships on every AC1800KD1 — verified before it leaves the facility.

Independently Verified RMS
Power rated and confirmed by independent testing. No peak figures. No asterisks. What's on the box is what measured on the bench.
1-Ohm Mono Stable
Standard across every AC Series monoblock. Run your sub at 1-ohm without derating, without thermal runaway, without compromise.
4-Layer SMD PCB
Double the copper layers of a standard build. Lower impedance power planes, better thermal dissipation, structural rigidity that survives the road.
LED Clipping Indicator
Real-time visual confirmation you're at max output without crossing into distortion. A tuning tool, not a decoration. Included standard — not an add-on.
Remote Bass Knob — In the Box
Driver-seat bass control ships with every unit. Not a $30 add-on. Not an optional accessory. In the box, ready to install.
Balanced Audiophile Inputs
Works with any source — factory OEM head units via high-level input, aftermarket receivers, or DSP processors. Input sensitivity spans 400mV to 20V. No additional adapter required to integrate with your existing setup.
Spectra-Core RGB Illumination — Integrated
No kit. No separate controller. Full RGB built into the chassis — addressable and ready to match your build from day one.
Tiffany-Style RCA Inputs
Chassis-mounted, gold-plated connectors — not the pressed-in budget RCAs standard at this price point. The threaded barrel locks the cable in place, eliminating the intermittent connection issues that develop over time from road vibration and repeated removal.
4-Way Protection — Always Active
Thermal shutdown, short-circuit, over-voltage, and under-voltage protection running simultaneously — not just during fault conditions. The amp protects itself and your speakers.
CMRR — Common-Mode Rejection
Alternator whine, ignition interference, and ground loop hum are the three most common noise sources in a vehicle install. CMRR identifies and cancels them at the point of entry — so you're not chasing a noise floor problem with ground loops and ferrite cores after the fact.

The Industry Sells
Numbers. We Sell
Results.

The category standard for amplifier marketing is a watt figure that looks great on a shelf tag and underdelivers the moment it's installed. Aunex was built to be the exception. Every AC1800KD1 ships with independently verified output — 1,800 watts RMS at 1 ohm, tested under real-world conditions, printed on the box without qualification. No peak figures. No asterisks. No fine print. Just the power we promised.

1800 verified watts rms