In a conventional full range compression driver the phase plug must be located extremely close to the diaphragm, excursion of the diaphragm is limited and middle frequency performance is compromised. A typical 2" dome compression driver has a limited high frequency response. Over 8 kHz the dome diaphragm breaks up causing resonance and harsh, metallic sound. The BMS annular midrange diaphragm covers the frequency range between 400 and 7.000 Hz with a smooth, linear response. The large diaphragm excursion of max. +/-0,8 mm results in high output and increased power handling up to 1.300 W peak. The ultra light annular diaphragm for the high range offers exceptional transient response with very high efficiency from 6 to 22 kHz.