CCTV has been broadcasting to the Chinese people since 1958 across a wealth of TV channels spanning from news and documentary to sports and comedy, entertainment and drama. Over the last couple of years, CCTV has gradually been moving to a new facility also located in Beijing – an iconic building designed by Rem Koolhaas and Ole Scheeren of Office for Metropolitan Architecture.
At the old facility, CCTV used TC Electronic DB4 transmission processors for their audio processing for several years, so it was a natural next step to upgrade the new facility with DB8 MKII units. At the new location, CCTV has five identical control rooms, each of which is capable of handling 10 TV channels. Two DB8 MKII units are used for each channel – one for processing and one as backup – so in total it adds up to 20 units in each control room; or 100 in total.
“We have inserted the DB8 MKII units into the signal chains of our broadcasting system and use them for loudness measuring as well as real-time loudness correction and upconversion from stereo to 5.1,” says Jiang Ming, chief broadcast engineer at CCTV. “The units are used in live broadcast transmissions, so reliability is absolutely key. We used TC’s DB4 units at the old CCTV site for years, and they never failed. Another important factor is that we want to control the loudness of the programs we broadcast, but at the same time we do not want to sacrifice the audio quality. We brought in a lot of different processors and carried out comprehensive tests, and ultimately the DB8 MKII units proved to perform the best.”
The DB8 MKII units are equipped with SDI I/O cards, and CCTV uses the ALC6 algorithm for loudness correction and UpCon HD for upconverting stereo signals to 5.1 plus two instances of the LM6 Radar Loudness Meter for measuring loudness at the input and the output stages. CCTV also makes use of the dual power supply feature, feeding the units simultaneously from two independent power sources to make sure the units can withstand a breakdown on one of the power feeds.
Further, the units are controlled via the TC Icon controller software and a tailor made solution has been installed for automatic per-program measuring and reporting of specific loudness descriptors. Finally, comprehensive SNMP trapping has been setup for system surveillance from the old CCTV site located 15 kilometers away from the new facility.