Quote: Exactly. Removing the damper also reduces acoustic impedance and increases treble, but increases it in higher parts, more linearly and does not cut down bass. The foam filter acts in the 3-7kHz area, while the damper acts in the 7-infty kHz area. Also the foam has a tendency to smoothen out peaks, the damper does not. The foam also increases apparent volume of the air by slowing the speed of sound - making for a virtually larger enclosure. There's more bass presence with dual dampers because you've cut off the treble so much, you had to increase volume to compensate. Am I right?