The MTS stereo signal can pass through a baseband converter for input to a stereo television. The composite MTS signal is also available for an internal or external decoder.
MTS uses signal matrixing for compatibility. Left and right channels are summed (L+R) for transmission in the normal 20Hz to 15kHz range. The stereo difference information (L-R) is transmitted on a subcarrier at 31.5 kHz.
The (L-R) signal is dBx companded to reduce noise. There is no companding of the (L+R) signal. As a consequence, stereo separation is optimized only at unity processing gain. There is a fairly wide volume control range over which acceptable separation is maintained, because separation as low as 10 dB yields subjectively pleasing stereo imaging.