Knowles TEC Series Balanced Armature Speakers are intended for use in high power hearing aids. TEC series combines output comparable to the larger BK receiver in an ultra-thin package. They have a medium DCR to impedance ratio and are a similar size to an EF receiver. The TEC Series operating sensitivity will not vary more than +1/-3dB from -17ºC to 63ºC. DTEC Series Balanced Armature Speakers (7.87 x 4.09 x 5.59mm)
combine two TEC speakers with a single round port. Case size is
equivalent to BK/EF. DTEC provides increased output and reduced
vibration compared to a single speaker.