( ) . . , . , . ? ( , ), . . , ? , . , , . . . . , , . , , . . . , . , , , . , , , , . , . 70- , . , , . , - , , . C . . 50-60- . 70- . 80- . , . , . 70- , . . . , , . . . - (A2) Nicam. . (.. FM-). . B/G ( 5,5M; 5,742M) D/K ( 6,5M; 6,258M) , (), . , , . (40-15000 Hz 40-20000) (-50 dB 70) . . . , , . , , . , , A2 (, ). , 1986 NICAM, , . NICAM D2-MAC. , 90- , NICAM . Nicam , . ( ) 728 /. , -. 14 16, 32 44,1 kHz. 30-15000 Hz. , 2. , .. 5,85 . Nicam, . , A2 Nicam. , , , . . . . , , . , . 50- . : , , , , . , , . , . Dolby Stereo. Dolby Stereo Dolby Laboratories (), , , Dolby Stereo. , . . . . Dolby Stereo 17500 . Dolby Surround , . Dolby Laboratories 80- Dolby Surround Sound (DSS) , Dolby Surround : , . . Dolby Surround Pro-Logic (DPL), : , , . DSS DPL , , , . Dolby Surround L (Left), C (Central), R (Right) S (Surround), - Lt (left-total) Rt (right-total). "total" () , "" ( ), - C S. L R Lt Rt - . Lt Rt. 3 ( "" ). S 3 , , , Lt Rt : (BPF) 100 7 - Dolby B-type Noise Reduction S +90 -90 , , S, Lt Rt, . , L R , . , - C S . : S Lt Rt. , . , C , Lt Rt. S, , , . S C : , Lt Rt, . , . , Rt Lt - , (crosstalk) S. THX , , , Dolby. Lucasfilm Ltd. . , Tom Holman's eXperiment ( ) , , . , . Dolby Pro-Logic, , - ( - ). (20-80 ), , ( ). . THX - THX Ultra. , , , Dolby Pro-Logic. , 5CH Cinema , . AC-3 DSS DPL , Dolby Digital AC-3 (Audio Coding - 3). 1992 , , 1994 - . -3 . (30-20000 ): - , , , (20-120 ) . -3, , . DVD. MPEG MultichannelMPEG Multichannel MPEG-2 Audio DVD . MPEG-2. AC-3 MPEG-2 Audio . , . DTSDTS (Digital Theater System) - , . , , . , , -3 - . |