This experimental study was conducted to identify the correlation between speaker design factors and T/S parameters. For experiments to be conducted in the study, the sample speakers modified the damper, sub-cone, and mass of diaphragm of woofer speaker for vehicles were made to find characteristics of mechanical factors of speaker and non-linear factors; and the sound pressure characteristics were investigated. The correlation between design factors and T/S parameters showed that the strength of suspension system and the mass of motor part increased with the increase of mass of cone paper; and the force factor and resonance frequency tended to exhibit different behaviors according to the changes of damper.