Here's some extra info I gathered...
(In Russian... original info excerpt)
1. Динамик LF +
2. Динамик RF +
3. Динамик LR +
4. TEL. MUTE
5. ACC
6. Динамик RR +
7. BUS
8. Динамик LF -
9. BAT +
10. Упр. громкостью
11. Динамик RF -
12. Динамик LR -
13. Подсветка
14. Динамик RR -
15. GND
16. Упр. антенной
(In English by Babelfish...

)
1. dynamic loudspeaker LF +
2. dynamic loudspeaker RF +
3. dynamic loudspeaker LR +
4. TEL. MUTE
5. ACC
6. dynamic loudspeaker RR +
7. BUS
8. dynamic loudspeaker LF -
9. BAT +
10. cont. by the loudness
11. dynamic loudspeaker RF -
12. dynamic loudspeaker LR -
13. illumination
14. dynamic loudspeaker RR -
15. gnd
16. cont. of the antenna