Class D vs Class AB Amplifiers | Which Is Better for Car Audio?

Class D vs Class AB Amplifiers

The amp class debate. Old-school Class AB vs modern Class D—here's what actually matters.

Quick Comparison

How They Work

Class AB

• Transistors always partially "on"
• Linear amplification
• Higher heat output
• Traditional design

Class D

• Transistors switch on/off rapidly
• PWM (pulse width modulation)
• Very efficient
• Modern design

Sound Quality Debate

The Old Argument

"Class AB sounds warmer, Class D sounds harsh"

The Reality (2026)

• Modern Class D rivals Class AB
• Top Class D (JL, Mosconi) is excellent
• Budget Class D may still have issues
• Personal preference matters

Efficiency Matters

Class AB Amp (50% efficient)

• 500W output needs ~1000W input
• Significant heat dissipation
• Larger heatsink required
• More alternator load

Class D Amp (90% efficient)

• 500W output needs ~555W input
• Minimal heat
• Compact size possible
• Less electrical stress

When to Choose Class AB

✅ Prefer "traditional" sound ✅ High-end SQ competition ✅ Have space available ✅ Budget isn't tight

When to Choose Class D

✅ Limited space ✅ Multiple amps needed ✅ Electrical system concerns ✅ Subwoofer amplification ✅ Modern efficient system

Best Applications

Top Recommendations

Class AB

• JL Audio XD series (hybrid)
• Arc Audio SE
• Mosconi Gladen

Class D

• JL Audio RD/VX series
• Alpine PDR/KTA series
• Kenwood Excelon XR

Bottom Line

Class D wins for most people:

• More efficient
• Smaller
• Cheaper to run
• Modern units sound great

Class AB for purists:

• Traditional sound
• Competition SQ
• Personal preference

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