All Grado headphones have a vented diaphragm design that incorporates a large air chamber. This design concept lowers the frequency resonance (distortion) of the diaphragm and extends bass response. The diaphragm is made of a low mass polymer, carefully formed to broaden resonant modes to reduce their amplitude. The diaphragm mass is determined with the compliance of the suspension in mind so that the desired low frequency resonance is achieved. The diaphragm's total mass is calculated to provide a full 20 KHZ bandwidth, while avoiding break-up at lower frequencies.
