🔰 BEGINNER LEVEL: What EQ Can and Cannot Fix

The Purpose of In-Car EQ

The frequency response measured at your ear in a car will never be flat. Unavoidable factors:

• Cabin resonances: The rectangular interior has standing wave modes that boost certain bass frequencies 6–15 dB
• Seat and glass reflections: Create comb-filtering peaks and dips in the midrange
• Driver placement asymmetry: Left and right paths differ, creating response differences
• Speaker roll-offs: Natural frequency limits of drivers

EQ corrects the response you measured, not the ideal response.

Important: EQ applied to a problem that isn't acoustic (a broken connection, a phase issue, a fundamentally incompatible crossover point) doesn't fix the problem — it compensates partially at the measurement position and may make other positions worse.

Fix problems first, EQ last.

Target Curves

A flat frequency response in-room is not the correct target for car audio. Research consistently shows that listeners prefer a specific curve with bass lift.

Harman Automotive Target Curve:

• +6 dB at 20 Hz relative to 300 Hz
• Flat from 300 Hz to 2 kHz
• Gentle −4 dB shelf above 10 kHz

Illustration note: Target curves comparison — Harman, flat, and measured system overlaid

Apply this as your EQ target. When REW shows your measured response, compare it to this target and add EQ filters to bring the measurement closer to the target.