The Main Parameters of GREELAN Digital Language Learning System

Digital Language Lab  Audio Data Switch:
●Of 128 44.1Khz/16bit audio data transmission, voice delay <1ms;
●Access to power supply: standard 220V ± 22V power supply, output voltage: 9V, intelligent switches, all the students to terminal power exchanged by audio host unified;
●SNR> 80dB, distortion <1%;
● Three-in-one network port (including power supply, control, communication, data exchange, high-definition VGA signal.


Student’s  Terminal :
●Continuously variable transmission to the same tune: 50% - +200%;
●SNR> 80dB;
●Frequency Response: 125Hz-10.0kHz (± 2dB), more than 16-bit linear sampling;
●The recording time ≥ 600 minutes;
●Direct drive VGA color LCD screen display.
●Three-in-one network port (including the feed, data communications, high-definition VGA signal)

RJ11 Port Headset :
●Headphones:
a)Frequency Response: 125Hz ~ 8000 Hz, ± 17 dB (0dB = 20uPa) (input power = 1mW);
b)Electrical Impedance: 32Ω ± 20%;
c) The characteristics of sound pressure  level (sensitivity):  ≥ 100dB/1mW (0dB = 20uPa).
●Microphone:
a)Frequency response :40-20000HZ
b)  Type: electrets microphone;
c)  Free field sensitivity: -47 ± 2 dB (0 dB = 1V/Pa);
d)  Directional type; two-way.