Introduction

SB-2000 series all-digital language learning system function index (SB-2000B is recommended)

1. System Technical Index

The product conforms to the National Education Technology Association "Digital Language Learning System Technical Specifications"

1. Adopt advanced ATM network protocol to perfectly solve the problems of voice delay, breakage and disconnection in the digital voice laboratory. Support one screen dual display

2. The load capacity of a teacher's main control computer is ≥100 student terminals;

3. The digital recording and storage of student terminal voice signals, the recording time of each student terminal is ≥50 minutes;

4. 32 groups of conversations in 64 seats, the dialogue sound delay is required to be within 5ms, and the time difference between sound and video is required to be within 5ms;

5. Frequency response: 20Hz ～ 10kHz (sampling rate is 22K or above, resolution is 16 bits or above)

6. The signal break time is zero; the distortion is less than 1%;

7. The variable speed does not change the function. Under the condition that the voice is not changed, the voice playback speed can be adjusted between 50% and 150%. Both teacher and student terminals are adjustable in speed.

8. Signal to noise ratio:> 60Db, crosstalk attenuation:> 70dB

9. Broadcast delay is required to be within 10ms

10. System startup success rate: 100%

11. Starting time: ≤3m

12. Wiring requirements, there are no plug-in components on the student's desktop to prevent student destruction.

13. Safety requirements: Student terminals are powered by safe voltage below 36V