Paris — If you are thinking about wirelessly connecting surround sound speakers to your home theater system, there's a choice beyond Bluetooth and Wi-Fi. Today Royal Philips Electronics will unveil yet another wireless technology, called Ensation, specifically tailored for high-end audio applications.
Designed to stream digital audio from PCs, home entertainment systems and other devices to multiple loudspeakers or wireless headsets, Ensation, operating at frequencies between 800 and 900 MHz, offers "robust, low-latency, CD-quality audio," said Rutton Ruttonsha, vice president and general manager for personal entertainment solutions at Philips Semiconductors. "This does audio only. It's designed for exceptionally high-quality audio."
Philips sees latency as the single biggest issue that has kept consumer electronics manufacturers from embracing any of the existing wireless technologies for their high-end audio systems. "By latency, I mean lips move and then, sound follows," Ruttonsha said.
Although existing wireless schemes including Bluetooth, Wi-Fi, infrared and analog FM have tried to enable audio applications, none of them offers "high-quality audio links" for multiple wirelessly connected speakers, for example, Ruttonsha claimed. "Many of those wireless technologies were originally developed to do one thing and later tweaked to do another," he said.
Philips' Ensation is a long-range, point-to-multipoint wireless technology with built-in features to ensure high-quality streaming audio. Ensation offers a variable net audio bit rate that can be set by system designers. Depending on required audio quality, its transmission data rate is between 150 and 500 kbits/second, according to Philips.
Ensation operates at a distance of about 30 meters indoors, assuming solid walls and concrete floors, as the range for speaker applications with 10-milliwatt transmit power. In contrast, Bluetooth needs about 100-mW transmit power to cover a home, according to Philips, as there is no 10-mW mode available in standard defined classes.
Ensation supports an infinite number of passive slaves (receivers only) and seven active slaves with return links. Although the scheme does not use frequency hopping, it comes with a data channel that allows bidirectional communication, according to Philips. Ensation monitors the interference on the network and gives feedback, so that the system can dynamically switch to adjacent channels with less interference.
Clearly, not everyone welcomes the Philips entry. "The consumer electronics industry doesn't need yet another technology to further confuse customers," said Kristine Overlaur, technical-marketing manager, North America, for CSR plc and marketing chair of the Bluetooth Special Interest Group.
Philips' Ruttonsha, however, argued that Ensation is "designed to eliminate the complexity associated with wireless audio networking." Ensation, which Philips believes can coexist with Bluetooth and Wi-Fi within a home, offers "high-quality, uninterrupted audio streaming, even in a noisy environment."
Philips is promising less than 20 milliseconds' latency for Ensation, compared with Bluetooth's latency of 40 to 50 ms and Wi-Fi's 100 ms or more. Research shows that consumers will recognize the latency when it takes more than 20 ms for sound to arrive. "We are the only vendor that has passed the Dolby latency requirement," said Ruttonsha.
The Dutch company has deliberately chosen not to put its new technology through an arduous standardization process. Targeting manufacturers desperate for a turnkey way to connect surround sound speakers or streaming digital audio from one room to another, Philips Semiconductors is launching a highly integrated two-chip wireless audio link — radio and baseband IC together — at $13 apiece in lots of 10,000 units. The chips are available today. Several manufacturers, including Philips Consumer Electronics, will hit the market during the Christmas season with Ensation-equipped wireless audio products, said Ruttonsha.
Neither Bluetooth nor Wi-Fi proponents are giving up the potential home audio market without a fight, however. The arguments for existing wireless technologies center on cost and availability.
"Bluetooth is here today, in production, and is shipping at a rate today of 5 million Bluetooth chips per week," CSR's Overlaur said. "Due to this high volume, the prices are well below $4 in volume. As long as the devices have Bluetooth in them and use the AV profile, high-quality audio applications can be enabled."
Similarly, Mike Stauffer, director of business development at Wi-Fi chip vendor Atheros Communications Inc., said, "A new technology [such as Ensation] with no volume might have difficulty competing." Stauffer said that "high-quality audio can be done within the 802.11 technology at a low cost, because 802.11 products are shipping in very high volumes."
The most notable Bluetooth audio products today are headsets. Overlaur, for example, talked of Bluetooth-enabled stereo headsets for listening to MP3 music streaming from a PC or a mobile phone.
As for Wi-Fi, Stauffer pointed to a new audio product from Sonos Inc. Based on Atheros' 802.11 chips, the system delivers a stereo audio stream from a server such as a PC to small, remote set-top-like devices around the home. The receiver device decodes and amplifies the audio stream, then outputs it to a pair of speakers connected to it with short wires.
Philips gets around the latency issue by using a broadcast system from the network to the Ensation masters and slaves. The important thing, the company said, is that Ensation does not retransmit the audio data, which could add to the latency. Rather, thanks to built-in error correction on the baseband IC, Ensation protects audio data from any transmission error.
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