Amplifier Runs Excessively Hot

Normal operating temperature: Warm to the touch (40–55°C). Uncomfortable but holdable. Too hot: Cannot hold hand on heatsink for more than 2 seconds (>65°C).

Causes:

1. Insufficient airflow — Most common. Amplifier mounted face-down in sealed trunk, upside-down, or with no clearance around heatsink.

Fix: Minimum 2–3 inches clearance above heatsink fins. Orient so fins are vertical (natural convection). Add a 12V fan if possible — even 50 CFM makes a dramatic difference.

2. Too much power for class — Class AB amplifier running 70% of rated power continuously at high ambient temperature.

Fix: Reduce volume or upgrade to Class D (generates 3–4× less heat for same output).

3. Low impedance load — 1Ω load on a Class AB amp generates enormous heat even at moderate power.

Fix: Rewire to higher impedance or use Class D amp rated for low impedance.

4. Clipping continuously — Clipped waveform has more average power than RMS, stressing amp beyond design limits.

Fix: Reduce gain, set correctly.