AudioControl A600.4 Review: Specifications, Installation and Comparisons
Quick summary: the buying decision
The A600.4 is a compact Class D amplifier from AudioControl's Altitude series, rated at 4 x 100 W RMS at 4 ohm and 4 x 150 W RMS at 2 ohm. High and low input modes let it take a factory speaker-level signal (up to 20 V) or an aftermarket preamp signal (up to 6 V), and practical features such as Valet Mode, ParaBASS and start-stop compliance make it an easy everyday upgrade.
AudioControl A600.4: what it is
The AudioControl A600.4 is a 4-channel amplifier from the Altitude series, with a sleek anodised matte grey aluminium chassis for heat dissipation. It delivers 4 x 100 W RMS at 4 ohm or 4 x 150 W RMS at 2 ohm.
Altitude amplifiers share an anodised matte grey aluminium chassis, high/low input modes, Linkwitz-Riley crossovers, ParaBASS bass processing and Valet Mode, which limits maximum volume to 25% when activated. The A600.4 offers four channels for front and rear speakers, or a front component set plus a bridged pair for a small subwoofer (300 W at 4 ohm bridged).
Key features
High and low input modes: preamp inputs up to 6 V and speaker-level inputs up to 20 V
Linkwitz-Riley crossover (off, high-pass or low-pass) from 50 Hz to 5 kHz, with ParaBASS bass processing
Valet Mode limits maximum volume to 25% when activated
Start-stop compliant and EV compliant up to 17 V, with GTO signal sense
Class D design with HEXFET power MOSFETs, a toroidal transformer and low-ESR capacitors; optional ACR-1 remote level control
Specifications explained
Rated power at 14.4 V is 4 x 100 W at 4 ohm and 4 x 150 W at 2 ohm, with 300 W bridged at 4 ohm. AudioControl quotes a signal-to-noise ratio of 107 dBA (ref. rated power) and THD+N of less than 0.21%.
There are 4 preamp inputs (line level up to 6 V, speaker level up to 20 V), a Linkwitz-Riley crossover that can be off, high-pass or low-pass from 50 Hz to 5 kHz, and ParaBASS low-frequency contouring.
Full specifications as published by AudioControl:
Model: A600.4
Type: 4-channel Class D amplifier
RMS power at 14.4 V, 4 ohm: 4 x 100 W
RMS power at 14.4 V, 2 ohm: 4 x 150 W
Bridged power, 4 ohm: 300 W
Preamp inputs: 4
Line-level input: 6 V max
Speaker-level input: 20 V max
Crossover: Linkwitz-Riley, off / high-pass / low-pass, 50 Hz – 5 kHz
Bass processing: ParaBASS
Signal-to-noise ratio: 107 dBA (ref. rated power)
THD+N: Less than 0.21%
Valet Mode: Yes
Power / ground wire: 4 AWG
Recommended fuse: 80 A
Remote level control: ACR-1 (optional)
Dimensions (W x D x H): 12.5 x 6.7 x 2.1 in
Weight: 7.2 lb
In the box: A600.4, manual, warranty card
Inputs: factory or aftermarket head unit
In high-input mode the A600.4 accepts speaker-level signals up to 20 V, which suits most factory head units. Premium factory amplifiers can put out more than that, so check the signal first; if it is higher, a line output converter such as the LC2i PRO (up to 40 V input) is the safer route. With an aftermarket head unit, use the RCA preamp outputs and low-input mode (up to 6 V). GTO signal sense can turn the amplifier on from the audio signal when no remote wire is available.
Crossovers, ParaBASS and everyday features
Use the high-pass filter to keep deep bass out of door speakers (start around 60 to 80 Hz and adjust by ear and measurement), and the low-pass filter for a subwoofer channel. ParaBASS adds adjustable low-frequency contouring. Valet Mode caps maximum volume at 25%, which is useful when the car is handed to a valet or service centre, and the amplifier is start-stop compliant and EV compliant up to 17 V.
Wiring and fusing
AudioControl specifies 4 AWG power and ground wire and an 80 A fuse. Fit the main fuse close to the battery, keep the ground short and on bare metal, and set gains with a test tone or an oscilloscope rather than by ear. An optional ACR-1 remote adds level control. The amplifier measures 12.5 x 6.7 x 2.1 in (W x D x H) and weighs 7.2 lb.
How it compares
Other multi-channel options at VA3 Car Studio:
AudioControl A1100.5: 4 x 90 W + 1 x 400 W RMS at 4 ohm, 4 x 125 W + 1 x 600 W at 2 ohm, ₹55,240
AudioControl EPICFOUR: 4 x 100 W RMS at 4 ohm, 4 x 200 W at 2 ohm, ₹31,440
AudioControl EPICFIVE: 4 x 75 W + 1 x 300 W RMS at 4 ohm, 4 x 150 W + 1 x 500 W at 2 ohm, 1 x 700 W at 1 ohm, ₹42,490
The EPIC amplifiers are line-level-input designs with more power per rupee; the Altitude models add speaker-level inputs, Valet Mode and start-stop compliance for everyday cars.
Price and value in India
At the time of writing (October 2026), VA3 Car Studio lists the A600.4 at ₹38,240, 15% below the MRP of ₹44,990. It is priced as a practical everyday amplifier, with features that matter in daily use rather than competition output. Prices can change, so the product page always shows the current price.
Verdict: who should shortlist the A600.4
The A600.4 is a sensible choice for an everyday car that keeps its factory head unit, or for an aftermarket head unit with modest power needs. For heavier power or app-based tuning, look at the EPIC or D-series amplifiers instead.
Real-world reviews and limitations
We have not yet published a VA3 installation report for the A600.4. The figures in this review are AudioControl's published specifications, not our own measurements, and real-world results depend on the installation, the wiring and the tune. If you have used one, we would welcome your feedback.
Frequently asked questions
How much power does the A600.4 deliver?
4 x 100 W RMS at 4 ohm or 4 x 150 W RMS at 2 ohm (14.4 V).
Can the A600.4 connect to a factory head unit?
Yes. In high-input mode it accepts speaker-level signals up to 20 V; above that, use a line output converter.
What does Valet Mode do on the A600.4?
When activated, it limits the maximum volume to 25%.
What fuse does the A600.4 need?
AudioControl recommends an 80 A fuse with 4 AWG power and ground wire.
Sources, pricing and related reading
Buy the AudioControl A600.4 Altitude 4-Channel Amplifier 600W RMS at VA3 Car Studio
VA3 guide: Car Audio Explained, Part 12: power, clipping, gain setting and noise
VA3 guide: Do you need an amplifier in your car sound system?
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