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About IEC711

writer:admin pubdate:2016-08-16 14:57 view:()

BELLSING Advanced miniature balanced armature (AMBA) receivers were designed for hearing aids, communication headsets, and hi-end in-ear earphone based on the small sizes, high efficiency.

The measurement is performed using the industry standard IEC60318–4 coupler previously known as IEC60711 coupler or just commonly the“711” coupler.
The coupler to receiver interface is done using fixtures like below:

The response data provided goes from 20-20kHz even though the 711 coupler is normally only specified to give reproducible results up to 10kHz. However, when using the same physical coupler unit comparison of the response of different receivers is possible.

Drive level
The drive voltage use is noted for the individual receivers. This is chosen so that the resulting output SPL is approximately 12dB lower than the output at which 10%THD occurs.

A note on amplifier output impedance
Response measurement data is obtained using an amplifier with output impedance lower than 0.1Ω. This is much lower than receiver impedance and results in a constant voltage drive. Some audio players will have output impedance that is on the order of thereceiver impedance. This will typically result in an attenuation of the low frequency response – e.g. lower bass. At higher frequencies, receiver impedance rises and becomes high compared to the output impedance of a typical audio player.

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