With the launch of HD, KTVN-TV in Reno, NV, also wanted to improve its audio chain. The station wanted to deliver HD images along with Dolby surround sound and a consistent audio level. It also needed to ensure that during Emergency Alert System (EAS) messages, the program audio was ducked and, finally, that EAS tests aren't run during commercial breaks. The solution was a Cobalt Digital Fusion3G 9985 loudness processor.
The processor was a perfect match for both current and future needs. It handles either an AES or embedded audio input, and it enables the upmixing of news and other sources to Dolby 5.1 surround. The result is consistent loudness without transition noise that some processors may produce in a viewer's surround decoder or satellite STB.
The software control of the 9985, which is mounted in an openGear frame, permits the station to easily make configuration changes as desired. The menu structure of the processor's software allows instant switching from AES to embedded audio inputs. The upmix feature adds flexibility in combining the audio channels to create a Dolby 5.1 surround sound. The result is a high-quality center channel, which often has important dialog that would be lost without the upmix feature.
One of the other important features is the ability of the device's closed-caption detector to move any captions that are not on line 9 to the correct line for transmission. Also, the unit includes a built-in frame synchronizer, which eliminates the HD-SDI switching glitches the station sometimes previously encountered. The result is a higher-quality feed to its 54 translators and the cable headends.
Managing EAS
Viewers need to hear the EAS message, and the Fusion3G 9985 can easily be set up as a program ducker that drops the program audio by 15dB upon activation. The feature ensures viewers get program reference level audio for the EAS message.
The processor is LAN- connected to a stand-alone control panel in MCR. This permits operators to view and change settings when required.
The station combined the loudness processor with a Dolby 568 loudness monitor, which results in sophisticated control and monitoring of TV station's audio channels. It can now both control and monitor loudness, measure and log discrepancies, and monitor the audio from any IP, AES, analog, HD-SDI embedded or SD-SDI sources.
Sophisticated audio processing
The 9985 provides 16 audio channels that can be used to route and process AES or embedded audio signals. KTVN uses the upmix function to create 5.1 surround-sound audio from news and other non-surround sources. (Monaural content on a stereo LR feed then appears in the upmix 5.1-channel Center channel.)
The station easily matched the volume levels of other stations in its market by comparing the off-air signals using the processor's output gain control. Using the general setting as a starting point for audio control, it was then easy to utilize the unit's other presets to sample the other audio configurations to find the best settings for different programs.
KTVN worked through the same process with the auto cross-fade speed functions for upmix, 5.1 detection threshold, center width and surround depth. The remote control panel is IP-controlled and is located in master control, so weekend operators can change levels for live sports or other shows.
In summary, the Fusion3G 9985 loudness processor is a sophisticated and versatile audio, surround-sound and caption controller.
Alan Nichols is the chief engineer for KTVN-TV.
