ZR vs SXE vs CANDY: Choosing a DS18 4-Channel Class D Amp

The deciding spec is RMS power at your speaker impedance

All three amplifiers are Class D 4-channel full-range models, but they are not interchangeable. The ZR600.4D, SXE-2000.4D and CANDY-XXL4B differ most in how much RMS power they deliver at 4 ohms, 2 ohms and bridged. That matters more than peak wattage because your speakers and subs see RMS power continuously.

Start by checking the impedance of your speakers or subwoofers. Then match that load to the amplifier’s published RMS ratings. A 4 x 150 watts RMS amplifier and a 3200 watt 4-channel amp are built for different system sizes, even if both carry four channels.

RMS power and load support side by side

The table below uses only the supplied catalog ratings. Where a rating is not listed for a product, it is not confirmed by the supplied information.

• DS18 ZR600.4D: 4 x 150W RMS at 4 ohms; 4 x 240W RMS at 2 ohms; 2 x 400W RMS bridged at 4 ohms. Minimum impedance is 2 ohms stereo or 4 ohms bridged. Peak rating is 2400W.
• DS18 SXE-2000.4D: 4 x 100W RMS at 4 ohms; 4 x 160W RMS at 2 ohms; 2 x 320W RMS bridged at 4 ohms. The catalog does not list a peak wattage for this model.
• DS18 CANDY-XXL4B: 4 x 220W RMS at 4 ohms; 4 x 400W RMS at 2 ohms; 2 x 750W RMS bridged at 4 ohms. Peak rating is 3200W.

ZR600.4D: the 4 x 150 watts RMS reference point

• ZR 4-Channel Class D Amplifier 4 x 150 Watts Rms @ 4-ohm: DS18 ZR600.4D ZR Class D 4-Channel Full Range Car Amplifier 150 x 4 @4 ohm Watts RMS This is the baseline 4 x 150 watts RMS rating. If your speakers are rated near that continuous power at 4 ohms, the ZR600.4D is the closest match of the three.

  

• ZR 4-Channel Class D Amplifier 4 x 150 Watts Rms @ 4-ohm: The ZR600.4D is made to deliver 2 x 400W RMS @ 4-Ohms Bridge, 4 x 240W RMS @ 2-Ohms, and 4 x 150W RMS @ 4-Ohms giving you the perfect power for your bass. Bridging two channels into a 4-ohm sub load gives you 400W RMS per bridged pair. That makes the ZR600.4D a practical choice for a four-speaker plus subwoofer system where the sub can take 400W.
• ZR 4-Channel Class D Amplifier 4 x 150 Watts Rms @ 4-ohm: The ZR600.4D offers a surplus of tuning options: Low pass, High pass, and Full Frequency Selector Switches, as well as Gain Knob to help tune any song to your frequency. Selectable FULL/LPF/HPF crossovers let you run front and rear speakers full-range while filtering a bridged sub pair, without adding an external crossover.

SXE-2000.4D: lower 4-ohm power in a compact chassis

• SXE Class D 4-Channel Amplifier 4 x 100 Watts RMS @ 4-Ohm 2000 Watts: SXE Class D 4-Channel Amplifier 4 x 100 Watts Rms @ 4-ohm At 100W RMS per channel at 4 ohms, the SXE-2000.4D sits below the ZR600.4D. It suits speakers with lower continuous power needs or builds where you want headroom rather than maximum output.

  

• SXE Class D 4-Channel Amplifier 4 x 100 Watts RMS @ 4-Ohm 2000 Watts: Prepare to be blown away by the SXE-2000.4D's staggering performance, delivering 320W x 2 CH bridged at 4-ohms, 160W x 4 CH at 2-ohms, and 100W x 4 CH at 4-ohms. Bridged output is 320W RMS per pair at 4 ohms, which is lower than the ZR600.4D’s 400W bridged rating. If your subwoofer needs more than 320W continuous, the SXE is not the stronger match.
• SXE Class D 4-Channel Amplifier 4 x 100 Watts RMS @ 4-Ohm 2000 Watts: The compact size of the SXE-2000.4D enables easy installation anywhere in your vehicle, making it a versatile companion for your custom audio setup. Space can decide an install. The catalog describes the SXE as compact, but it does not give exact dimensions, so measure your mounting location before committing.

CANDY-XXL4B: the 3200 watt 4-channel option

• CANDY Compact Full-Range Class D 4-Channel Amplifier 3200 Watts: The CANDY-XXL4B delivers 3200W peak resulting in clean RMS output across all channels at: 4 x 220W @ 4Ω, 4 x 400W RMS @ 2Ω, and 2 x 750W @ 4Ω Bridged! The CANDY-XXL4B is the highest-output amp in this comparison at every listed load. Its 220W per channel at 4 ohms and 750W bridged per pair suit larger speaker and subwoofer systems.
• CANDY Compact Full-Range Class D 4-Channel Amplifier 3200 Watts: Fine-tune your system with adjustable crossovers (40Hz–2kHz) and selectable bass boost (0/6/12dB). The crossover range and bass boost give you tuning control that the ZR and SXE records do not describe in the same detail. That helps when matching different speakers in one vehicle.
• CANDY Compact Full-Range Class D 4-Channel Amplifier 3200 Watts: Drop it in fast with Hi-Level Inputs and Auto Turn-On — perfect for factory system upgrades. Hi-level inputs and auto turn-on let the CANDY-XXL4B accept factory speaker-level signals without a separate line-output converter, which simplifies integration with a stock head unit.

Installation features that change the choice

The CANDY-XXL4B lists hi-level inputs and auto turn-on, which are useful when you keep the factory radio. The ZR600.4D lists low-level and high-level input range plus selectable FULL/LPF/HPF crossovers and a gain knob. The SXE-2000.4D lists a selectable crossover and multi-channel design, but the supplied record does not confirm hi-level inputs or auto turn-on.

Fusing and wiring also differ. The ZR600.4D record lists 4-gauge power and ground terminals and 2 x 30A fuses. The CANDY-XXL4B record lists dual 50A fuses. The SXE record does not confirm fuse ratings or terminal size in the supplied information. Check your wiring kit against the amplifier you choose rather than assuming they are the same.

Which amp fits your build

• You want a 4 x 150 watts RMS amplifier for four speakers: Choose the ZR600.4D if your door or rear speakers are rated around 150W RMS at 4 ohms and you may later bridge two channels for a 400W sub.
• You need a compact full-range Class D amp for modest speakers: Choose the SXE-2000.4D if 100W RMS per channel at 4 ohms matches your speakers and you value a smaller chassis over maximum output. Confirm the mounting space because exact dimensions are not supplied.
• You are building a high-output system or upgrading a factory radio: Choose the CANDY-XXL4B if you need 220W per channel at 4 ohms, 750W bridged per pair, or hi-level inputs with auto turn-on. Its 3200W peak rating reflects peak, not continuous, output.

What the catalog does not settle

The supplied records do not include measured sound quality, distortion figures for the CANDY-XXL4B, or exact dimensions for the SXE-2000.4D. Those gaps mean you should treat marketing language such as “clean signal” or “staggering performance” as manufacturer claims, not proven results. Use the RMS and impedance ratings to make the decision, and verify physical fit and wiring requirements before purchase.