Option Audio AIR-D4 Amp 4 Channel Class D Compact Amplifier 330w RMS
Product Description
The Option Audio AIR-D4 is a 4-channel Class D micro-format car amplifier delivering 330W RMS bridged, with high-level inputs and auto turn-on. It is part of the Option Audio AIR amplifier range.
Also in the range: AIR-D1 mono subwoofer amplifier and AIR-D6 6-channel amplifier.
Key specifications
- Channels: 4, Class D
- RMS power (4 ohms): 100W
- RMS power (2 ohms): 165W
- RMS power bridged (4 ohms): 330W total
- Frequency response: 20Hz–20kHz
- High-pass and low-pass filters: 40Hz–400Hz
- Minimum impedance: 2 ohms
- Inputs: high-level with auto turn-on
- Dimensions (W x H x D): 105.7 x 41.7 x 208mm
- Recommended cable: 10mm²
Option Audio AIR-D4 4-Channel Amplifier
Compact power upgrade: The AIR-D4 is a 4-channel Class D amplifier that delivers significantly more dynamics and volume than running speakers directly from a factory head unit.
Ultra-compact dimensions: At just 105.7 x 41.7 x 208mm, the AIR-D4 fits behind a dashboard, in a glovebox, or under a seat — ideal for modern vehicles with limited installation space.
Plug-and-play with factory systems: Built-in high-level inputs and auto turn-on mean no separate remote cable is needed. The amplifier detects the speaker signal directly, making it straightforward to integrate with an original radio.
Flexible 4-channel configuration: Power front and rear speakers simultaneously, or bridge two channels to run a front system alongside a subwoofer.
Class D efficiency: The Class D circuit keeps heat generation and power consumption low, maintaining stable sound quality without stressing the vehicle's electrical system.
Specifications
- Class-D power amplifier: Yes
- Operating voltage: 10-16V
- RMS power (4 ohms): 100 watts
- RMS power (2 ohms): 165 watts
- RMS power bridged (4 ohms): 330 watts total
- RMS power bridged (2 ohms): not possible
- Frequency response: 20Hz-20kHz
- High-pass filter: 40Hz-400Hz
- Low-pass filter: 40Hz-400Hz
- Total harmonic distortion (THD): <0.1%
- Minimum loudspeaker impedance: 2 ohms
- Signal-to-noise ratio (A-weighted): >90 dB
- Security: 60A
- Dimensions (W x H x D): 105.7mm x 41.7mm x 208mm
- Cable cross-section (recommended): 10mm²
What's In The Box
- OPTION AIR-D4 4-channel amplifier
- Subwoofer level remote control including Velcro strap for flexible mounting
- 2x Plug & Play adapters for input signal to RCA
- 1x Plug & Play adapter for output signal to Molex
- 1x Plug & Play adapter for output signal to loose ends
- 1x Plug & Play Adapter Line Out for connecting an additional power amplifier/active subwoofer
- Mounting/fastening plates including 6 screws (for mounting on the amplifier) and 4 screws (for mounting in the vehicle)
- Allen key
Delivery & Returns
Free UK delivery. Orders placed before 2pm Monday–Friday are dispatched the same day from our Nottingham premises. Tracking is uploaded to your eBay order automatically.
30-day returns. Changed your mind? Return the item unused in its original packaging within 30 days for a full refund. Your statutory rights are unaffected.
Frequently Asked Questions
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About CEN
CEN is a UK specialist in car audio, dash cams, home audio and outdoor tech, based in Nottingham. Our staff have decades of combined experience in electronics, engineering and automotive businesses, and we're authorised retailers of the industry's most trusted manufacturers — every product backed by official UK support and warranties.
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