limited, or is done over 3G/4G cellular data links”. Another codec manufacturer using the AAC range is Comrex. Director of sales and marketing
Comrex introduced its first IP model in 2005, since when, says Crump, there has been “nothing but exponential growth in IP codec technologies”. This is
“Most of our customers demand professional broadcast quality with good security. For that,
dedicated hardware audio codecs are still the best"
Chris Crump comments that with its ongoing research, Fraunhofer IIS continues to make “incredible progress in achieving higher quality at very low data rates with minimal latency”. As to how much better that can get, he says it remains to be seen and heard: “I think as processors get smaller and more powerful, our development will continue in the same manner that it has for the past five decades.”
Gustavo Robles, AEQ
reflected in Comrex’s key market, radio. “Most of the major radio broadcasters have embraced IP codec technology because it provides complete mobility due to the large number of publicly available wireless data services,” says Crump. “With satellite IP data services like Inmarsat BGAN, our customers can broadcast from 95% of the Earth’s landmass and even at sea.”
Radio reporting was instrumental in IP gaining a strong foothold in the broadcasting market. A manufacturer that caters for this field is Tieline, which will be showing a Mic Adapter for the Report-IT app during NAB 2012. This interface enables professional dynamic mics to be connected to an iPhone 4, allowing it to handle 20Hz- 20kHz CD quality audio.
THE FUTURE OF BROADCASTING Tieline spokesman Glenn Davies says the company sees Audio over IP as “the future of broadcasting”, particularly with the dismantling of the analogue leased line and synchronous network infrastructure, including ISDN. “Audio over IP has the flexibility to adapt to meet the changing needs of technology,” he observes. Davies acknowledges that
convincing the majority of engineers over “the merits of
IP” took some time but says, “Eventually weight of numbers and data clearly showing its advantages over synchronous networks has made IP the predominant coding transport for audio. 3G, 4G and WiFi can be used to broadcast live over IP generally and are easily accessible these days. ISDN and POTS [plain old telephone service] are still used at venues for sports events broadcasting and the like, but increasingly we are seeing broadcasters use wired IP with ISDN and POTS as a backup as it’s cheaper and highly reliable these days.” Telos is seeing its IP codecs
used for both contributions and transmission. “Users of Telos and other IP codecs are distributing programming via IP-audio daily to thousands of destinations,” says Harnack. “Some of this is over satellite-based IP-audio. There are now many dozens if not hundreds of smaller program distribution networks for local and regional sports and
TECHNOLOGIES –PART 1 The AAC family
Developed by companies including Fraunhoffer IIS, AT&T Bell Laboratories, Dolby Laboratories, Sony Corporation and Nokia, Advanced Audio Coding was recognised as an international standard by the Moving Picture Experts Group (MPEG) in 1997. AAC offered sample frequencies from 8-96kHz, compared to the 16-48kHz of MP3 music compression, which it was designed to succeed. It is part of the MPEG-4 specification for good quality coding at low bit rates and has been expanded to include AAC-LD (low delay), AAC-ELD (enhanced low delay), HD (high definition)-AAC, HE (high efficiency)-AAC and, most recently, Extended HD-AAC.
Handcrafted and individually calibrated, the 8260A three-way DSP monitor is simply a masterpiece of electro-acoustic design. The aluminum enclosure is perfectly integrated with the new Minimum Diffraction Coaxial midrange/ tweeter and houses all the cutting edge technologies Genelec has developed over the past thirty years. Thanks to the fully automated AutoCal calibration module, the monitors sound exactly as expected, even in challenging acoustic when only the best will do.