Lexicon 5-2-5 Matrix Systems Manual 

27, Since the matrix elements have symmetry about the left/right axis, the values of CL and CR for right steering can be found by swapping CL and CR. See Figure 17. Figure 17: The Center Left matrix element in the ’89 Patent (and Pro- Logic). The value at the center of the plane, the…

4, Lexicon 5-2-5 Matrix Systems of the amplitudes of the sum and the difference of the input channels. We will not discuss the method for determining these steering directions in this paper, although Logic7 differs from standard decoders significantly in how this is done. These issues will be covered in another paper. …

31, Lets assume the center channel is reduced in level by 4.5 dB below the level in our ’89 decoder, or –7.5dB total attenuation. –7.5dB equals 0.42. The matrix elements for the center can be multiplied by this factor, and a new center boost function (GC) can be defined. For front steeri…

16, LRL = .71 – .71*G(lr) + .41*.71*G(cs) LRR = -.71 + .41*.71*G(cs) For the rear left LRL = .71*(1 - G(lr)+.41*G(-cs)) LRR = .71*(1 + .41*G(-cs)) (the right half of the plane is identical but switches lrl and lrr.) The rear matrix elements in the Dolby Pro-Logic are For the front left quadrant LRL = …

39, shifted path for the rear channels is a 90 degree phase difference between the output channels A and B. This results in an unsteered signal, which is what we want. In discussions at the IRT Munich I discovered that there is a European standard surround encoder. This encoder simply att…

33, Power from the center PC = GC^2*(Lin^2+Rin^2) + 2*GC^2*Cin^2 Power from the rears depends on the matrix elements we use. We will assume the rear channels are attenuated by three dB during forward steering, and that LRL is cos(cs) and LRR is sin(cs). From a single speaker PREAR = (.71*(cos…