Crystal Vision
Using the front control panel
TANDEM 3G User Manual R1.4
42
23/04/2012
PCM Audio delay
Rotate the shaft control to show the Audio delay menu.
Press F1 and rotate the shaft control to adjust.
-20 to +80ms.
Output embedder
pattern
Rotate the shaft control to show the output embedder pattern menu.
Press ENTER and rotate SCROLL/ADJ. to select.
Sony, SMPTE.
Audio controls
Output Group Enable
The four output embedders can be individually enabled or disabled, this allows for any other
data already present on the input video to be retained for down-stream use. If required the
ancillary data can also be removed by enabling the VANC blanking.
Audio Gains
In total there are 32 audio gain controls, one for each of the 16 channels of de-embedded audio
and 16 channels of AES audio. The gain controls will give
18dB of gain relative to the input
level up to the point where digital clipping will occur.
Audio delay
These controls can be used to delay the audio with respect to the video by up to 80ms and
compensate for any small delay between the incoming video and audio signals. This audio
delay can be applied individually to each of the de-embedded groups and individual AES
stereo pairs by selecting them to be delayed or not delayed. The delay is applied at the output
of the router and is a single global control set in the audio delay menu.
Stereo to Mono conversion
For the purposes of this discussion it is assumed that all inputs are stereo pairs and that each
half of the stereo pair is on a consecutive input i.e. input 1 and input 2 are a stereo pair, input 3
and input 4 are a stereo pair, etc.
The action of converting a stereo pair to a mono output is simply a summing process followed
by a gain correction. The gain correction is necessary because when the two components of a
stereo signal are summed, a 6dB increase in output level will result; this will then need to be
corrected to maintain unity gain.
The action of selection will cause that channel to output the mono sum of itself and its
associated channel. The associated channel output will still output its unaltered programme.
Either channel of a pair can be selected for stereo to mono conversion.
Example: Selecting channel 1 for mono conversion will result in channel 1 outputting the
converted mono sum of channels 1 and 2. Channel 2 will remain outputting the original
channel 2 programme. Similarly deselecting channel 1 and selecting channel 2 will cause
channel 2 to output the converted mono programme and channel 1 the original channel 1
programme.
Note:
When transporting Dolby E, to ensure integrity of the audio any Dolby E stream must be
treated as a stereo pair and no audio processing such as mute, mono and gain is applied.
