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Surround and apt-X Live

Supply Side is an occasional conversation with suppliers in the news. RW spoke with APT Commercial Director Jon McClintock.

Supply Side is an occasional conversation with suppliers in the news. RW spoke with APT Commercial Director Jon McClintock.

RW: You rolled out apt-X Live last fall. What is it and why might radio be interested?

McClintock: apt-X Live is the latest algorithm from APT’s stable. It concentrates on our core strengths, low delay and acoustic integrity; and it adds increased channel density to the feature set.

It has an 8:1 compression ratio, which in effect means a 15 kHz stereo signal over 128 kilobits per second — be it ISDN, or 2 x timeslots on a T1, or an IP network. Acoustically it sounds excellent; and this has been substantiated by independent blind listening tests, where it performed favorably compared to PCM. Delay-wise, it has an encode/decode latency of 1.9 milliseconds.

For stations, apt-X Live is ideal for real-time applications where they need to be connected for remotes, STLs and studio-to-studio networking. We also know it will assist live performance events where analog wireless mics may become redundant due to the impending spectrum squeeze.

Another application is embedding 16 channels into an AES3 stream for HDTV applications. Current technology is limited to eight with Dolby E.

RW: APT has made changes in its staff and offices here.

McClintock: The U.S. and Canada are great markets for APT and to service the needs of the broadcasters we recently opened offices in both Boston and Florida.

Kevin Campbell, who was APT’s European Sales Manager, has moved to Boston and brings a depth of application knowledge and commercial acumen for broadcasters who are considering investing in codecs for HD or traditional FM/AM links.

In Florida, we were very lucky in securing the services of Ted Nahil, who brings a wealth of knowledge, experience and respect to the APT product line. Ted has worked both sides of the fence, as a user and a technology provider, and understands the challenges to both.

RW: You recently took an order for 20 WorldNet Oslos to use in a pilot surround sound project with the European Broadcasting Union. What’s going on with 5.1 for radio?

McClintock: Surround sound for radio is going to be a hot topic over the next five to 10 years.

HD Radio and DAB were really incremental improvements to FM. For a listener to immerse themselves in a 5.1 program will be a fundamental improvement on the listening experience.

The EBU is investing now in 5.1 to share content within the 50 member public service broadcasters in Europe. The pilot project has decreed that Enhanced apt-X is the algorithm of choice for sharing content and the WorldNet Oslo is the architecture to house the algorithm.

The emission standards will be the usual suspects, i.e. Dolby, DTS or SRS. Where we are involved is the movement of content from source, i.e. remotes, through to the station and then onto the transmission site. Using Enhanced apt-X will retain the spectral imaging — an issue that becomes more important with multi-channel — and continue to ensure acoustic integrity.

RW: The EBU also has made recommendations concerning audio over IP that involve Enhanced apt-X?

McClintock: The EBU has been active to ensure that the issue of multiple algorithms, both compression and bonding, and lack of compatibility which littered the broadcast industry for ISDN is not repeated for IP.

They’re working with manufacturers to agree on a series of standards. Enhanced apt-X has been decreed as an Optional Algorithm, which is a tremendous validation for APT.

RW: What else should U.S. radio buyers look for from APT at spring NAB?

McClintock: I think the issue that is high on the broadcasters’ agenda today is audio over IP.

APT has been very active in this field for several years and offers a range of products from a simple stereo 1 U unit, the WorldCast Horizon, up to the highly sophisticated WorldNet Oslo, which offers multiple audio channels and several levels of redundancy in a modular format.

We will be launching new products that support several algorithms and transport protocols, controlled via a highly intuitive and versatile GUI.

For information about APT products call (800) 955-APTX or visit