Community

AES Journal Forum

A Compatible System of Stereo Transmission by FM Multiplex

Document Thumbnail

A method of applying modulation to the channels of a stereo FM multiplex transmitter is described which provides a -compatible- reception for the monaural listener. By transmitting an additive combination of the microphones on the main channel of the FM transmitter and a subtractive combination on the sub-carrier channel, the main channel transmits a balanced program without the deterioration which would be brought about if the output of only one microphone were transmitted on the main channel. At the receiver the combinations are separated so that the microphones feed the individual loudspeakers directly. Additional advantages of the system include a 6 db signal-to-noise gain for the sub-carrier channel. This gain is highly desirable because the relatively poor signal-to-noise on the subcarrier channel curtails the distance range of the stereo transmission. In addition, the signal-to-noise ratio appearing in the receiver channel is made identical so that disturbances due to noise appear symmetrically in both loudspeakers. This results in less annoyance due to noise. A discussion of relative signal-to-noise ratios on the main channel and sub-carrier channels is given, together with recommendations for optimum performance of a stereo transmission.

Author:
Affiliation:
JAES Volume 6 Issue 2 pp. 70-73; April 1958
Publication Date:

Click to purchase paper as a non-member or you can login as an AES member to see more options.

No AES members have commented on this paper yet.

Subscribe to this discussion

RSS Feed To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.

Start a discussion!

If you would like to start a discussion about this paper and are an AES member then you can login here:
Username:
Password:

If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.

AES - Audio Engineering Society