Dolby Digital: Line or RF - which is better?
In the settings of Dolby Digital decoders you will find the two options "Line" and "RF". We'll tell you which of the modes is better and what exactly the two options do.
Dolby stream settings: Line or RF?
The two settings "Line" and "RF" refer to the Dynamic Range Control of Dolby Streams. These settings are transferred in the audio stream metadata:
- If you activate the Dynamic Range Control, you can adjust the maximum level of the signal. Loud parts of the film are thus attenuated and the level of quiet scenes is increased. This is why the dynamic control is also called "post-mode".
- So you can watch movies without constantly adjusting the volume with the remote control. Dolby distinguishes between the two profiles "RF" and "Line" for dynamic control.
- The name of the profile "RF" comes from "Radio Frequency", since this is often used for signals that are received by radio. This applies to TV reception, for example.
- The RF profile pretty rigorously brings the audio signal to an almost identical volume level throughout.
- In line mode, the signal is not so strongly compressed in the dynamics (note: do not confuse the dynamic compression with the compression of the data rate). This means that the loudest parts are quieter than in the original, but nevertheless much louder than in the RF profile. The opposite is true for the quiet parts.
- In many cases you can adjust the levels yourself in the line profile and experiment with them.
- It is therefore best to test the line profile first. If the compression is not enough for you, you can switch to "RF".
Via HDMI you can transmit Dolby Digital either via Bitstream or PCM. We explain the exact difference between the two standards.