May presage new generation of audio semiconductors -- Smart speakers for PCs?
In the often-clamorous world of PC audio, a handful of manufacturers are beginning to make a new noise about turning passive analog speakers into a new type of intelligent appliance-a smart digital speaker. Although not everyone is convinced that such devices, which receive and decode audio streams, will be a hit, these new peripherals, made possible in part by the rise of serial digital data buses such as the Universal Serial Bus (USB) or 1394, may drive forward a new generation of audio semiconductors.
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A case in point is the ADA 315 digital speaker system that will be announced this week by Altec Lansing Technologies Inc. (Milford, Pa.). It is among the first of a generation of speakers that use USB (and the Windows user interface) to transfer full-fidelity six-channel audio between speakers and the host entertainment console, in this case a PC.
The digital speaker is effectively a black box, like other USB peripherals, that can be hot-plugged into a bus and will immediately identify what it is and how it is to be configured. In fact, it is more a smart speaker than a digital one, said Tommy Freadman, Altec Lansing's executive vice president for engineering.
Altec is not alone is pursuing this vision. The DSS350 speakers demonstrated by Philips Electronics (Sunnyvale, Calif.) at last fall's Comdex also use USB as a digital channel to send audio directly to a speaker that has the processing muscle to decode it. And Creative Labs, capitalizing on its acquisition of Cambridge Sound, will introduce this year a digital speaker system geared for 5.1-channel Dolby Digital playback. Also, Yamaha (San Jose, Calif.) similarly demonstrated USB speakers at last fall's Comdex, but has made no decision yet to market them.
ot everyone agrees that speakers should become the smart digital audio-processing devices of the future. Despite Creative Labs' product plans, it is interested in keeping the audio converter on a PC sound card and using analog amplifiers to talk to traditional passive speaker systems, said Micah Stroud, audio product marketing manager for the Americas.
"Digital speakers are a great solution-if everything is Dolby Digital," Stroud said. But "USB [as an interface to digital speakers] is not a dream picture." The real world, as he described it, includes diverse audio playback requirements including MPEG, RealAudio and WaveTable synthesis. "The digital speaker moves the cost of the sound card out to the speaker," said Stroud; moreover, he added, unlike a PC-based sound card a digital speaker is "a nonupgradable item."
That view is characteristic of a number of audio IC makers trying to hold on to design wins for processing done inside a PC. Still, it is a position that even Creative Labs-the father of PC audio with its SoundBlaster technology-has found hard to stick to.
The success of its Encore Dxr2 PC-based DVD player has encouraged the company to develop its own system for 5.1-channel Dolby Digital playback. The development also capitalizes on the miniature-speaker technology that Creative acquired with Cambridge Sound. Code-named Snowball, the Creative AC-3 player includes two electronic sections, one placed relatively close to the PC, the other residing within a separate powered subwoofer cabinet. The box close to the PC serves as a hub, gathering the analog inputs from a legacy sound card and/or the digital inputs from the DVD player or Sony-Philips Digital Interface source. The powered sub-woofer includes a full AC-3 decoder, D/A converters and power amplifiers for the subwoofer and five other connected speakers.
Overall, the new speaker systems from Philips, Altec Lansing and others-even an experimental audiophile speaker system constructed by Sony Electronics-point to an entirely different generation of audio components.
Digital speakers will demand new types of DSPs, data converters, audio power amplifiers and, to some extent, "virtualization" processors. Digital speaker systems, explained Altec Lansing's Freadman, require a digital interface to the console, a DSP, D/A converters and audio amplifiers-all within the speaker cabinet.
Specifically, the ADA 315 uses a DSP for Dolby Digital (AC-3) decoding and a pair of "side-firing" speakers in the left and right stereo speaker boxes to give left rear and right rear surround sound. A third box serves as a center channel and low-bass subwoofer.
Ordinarily, Dolby Digital Surround Sound decoding maps to six speakers (sometimes called 5.1 speakers): right front, left front, center front, right rear, left rear and a somewhat directionless low-frequency subwoofer. To play them to full effect, the user needs six speakers and amplifiers. But this can be too complicated for the average PC user, said Freadman, and too expensive for the new generation of sub-$1,000 PCs that will use the host CPU for DVD movie decoding. Here, separate speakers with built-in decoders and amplifiers will provide full surround-sound effects and offload this task from the host. The ADA 315, like the ADA 310 (a Sony-Philips Digital Interface system shown at Comdex), puts six speakers-along with all the decoding electronics, USB-connected audio DACs and miniature 10-W amplifiers (a 24-W amp for the subwoofer)-in a USB-connected three-box system.
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The current generation of digital speakers use USB, with Class A-B amplifiers in small packages. But in future generations, said Freadman, the digital interface will look like 1394 or some kind of pulse-code used to modulate high-efficiency Class D switching amplifiers. "About the only part of the speaker that will remain analog," said Freadman, "is the diaphragm."
Just like the developers of audio sound chips and 3-D-sound processors, Altec Lansing sees PCs as home entertainment consoles. Unlike the developers who looked for ways to extend SoundBlaster compatibility to the PCI bus and enhance the game-playing experience on Windows 95 platforms, Altec and others see PCs as DVD movie-playback machines. While the inexpensive platforms will use the host CPU to decode DVD video (generally in an MPEG-2 format), the Dolby Digital audio will be decoded by a peripheral device far removed from the motherboard and its PCI bus.
DSPs in the speaker system will accommodate multichannel formats like Dolby Digital (AC-3). They will not necessarily promote 3-D "virtualization," said Freadman. Virtualization, or "3-D" audio, is a means of creating 3-D sound effects with just two stereo speakers. For example, head-related transfer function (HRTF) algorithms emulate human ear canals in the way they pick up sounds from different positions about the listener. In effect, the listener is tricked into hearing footsteps behind him (or bombs exploding overhead), when in fact all of the sound is produced by front speakers. Because of the need to produce dramatic effects with just two speakers, many of the virtualization algorithms developed by companies like QSound Labs Inc. (Calgary, B.C.), Spatializer Audio Laboratories, Inc. (Mountain View, Calif.), Aureal Semiconductor (Fremont, Calif.), EuPhonics Inc. (Boulder, Colo.) and SRS Labs Inc. (Irvine, Calif.) have their best utility with 3-D Windows games.
Dolby AC-3, in contrast, is a full 5.1-speaker surround sound, rather than an emulation. "Multichannel requires multiple channels," insisted Freadman. "We believe in delivering full multichannel sound to the user. Even if the sound is mixed down to two speakers, the AC-3 information is sent to the speakers." It is most convenient to download five-channel audio to the speaker system, then mix down to two, said Freadman.
Thus, the DSPs that will be used for this will probably not be PCI interface components like the Crystal Semiconductor (Austin, Texas) CS4610 SoundFusion PCI audio accelerator and CS4297 AC-97 codec combination. Nor will it be the ThunderBird 128, an audio accelerator chip developed by VLSI Technology (San Jose, Calif.) and Qsound Labs, or the SoundMax64, a development of Analog Devices (Norwood, Mass.) and EuPhonics. Rather, they may be more general-purpose programmable parts like the DSP56362 from Motorola's Semiconductor Products Sector (Austin, Texas) or the ZR38600 by Zoran (Santa Clara, Calif.). The latter, said Zoran's Paul Goldberg, audio products vice president, is the engine behind Altec Lansing's side-firing 310 and 315 digital speakers.
These 24-bit fixed-point devices have displaced 16-bit devices once used for audio signal processing. But even the 24-bit models may not provide the precision, dynamic range and interface-juggling capability demanded for next-generation audio systems, said Maria Tagliaferro, DSP product marketing manager at Analog Devices. "I think 24 bits is a dying architecture," she said. Her company has produced a $10 version of its 32-bit Sharc processor, which it believes will steal audio slots from other general-purpose DSPs. It is likely, though, that this area will drift toward custom or special-purpose DSPs. For example, Crystal Semiconductor's CS4926 standalone processor is targeting home theater with Dolby AC-3 and Digital Theatre Systems (Westlake Village, Calif.) decoding algorithms in hardware.
Noting this trend toward out-of-box processing, Medianix Semiconductor (Mountain View, Calif.) has developed a series of proprietary 24-bit DSPs that sit in the pathway between host-PC, standalone DVD player, stereo entertainment console or system.
The current generation of Medianix processors, like the MED25006 used in the MediaTheater speaker system developed by Boston Acoustics (Peabody, Mass.), decode Dolby Pro Logic. Upcoming versions of the Medianix DSP will employ Dolby Digital decoding with either full six-speaker surround sound or a virtualized field with two speakers. The MED25201, for example, is a full six-channel Dolby Digital (AC-3) decoder and a version of this device-the MED25202-will decode AC-3 but virtualize it for two speakers.
In fact, the company has alliances with the major algorithm developers including Dolby Laboratories, Harmon Interactive Group, SRS Labs and Spatializer Audio Labs.
These devices can take a variety of input formats, said a senior product marketing manager, but outside of the PC, it will not likely be AC-97.
Copyright 1998 CMP Media Inc.
In the often-clamorous world of PC audio, a handful of manufacturers are beginning to make a new noise about turning passive analog speakers into a new type of intelligent appliance-a smart digital speaker. Although not everyone is convinced that such devices, which receive and decode audio streams, will be a hit, these new peripherals, made possible in part by the rise of serial digital data buses such as the Universal Serial Bus (USB) or 1394, may drive forward a new generation of audio semiconductors.
FOR MORE INFORMATION:
A case in point is the ADA 315 digital speaker system that will be announced this week by Altec Lansing Technologies Inc. (Milford, Pa.). It is among the first of a generation of speakers that use USB (and the Windows user interface) to transfer full-fidelity six-channel audio between speakers and the host entertainment console, in this case a PC.
The digital speaker is effectively a black box, like other USB peripherals, that can be hot-plugged into a bus and will immediately identify what it is and how it is to be configured. In fact, it is more a smart speaker than a digital one, said Tommy Freadman, Altec Lansing's executive vice president for engineering.
Altec is not alone is pursuing this vision. The DSS350 speakers demonstrated by Philips Electronics (Sunnyvale, Calif.) at last fall's Comdex also use USB as a digital channel to send audio directly to a speaker that has the processing muscle to decode it. And Creative Labs, capitalizing on its acquisition of Cambridge Sound, will introduce this year a digital speaker system geared for 5.1-channel Dolby Digital playback. Also, Yamaha (San Jose, Calif.) similarly demonstrated USB speakers at last fall's Comdex, but has made no decision yet to market them.
ot everyone agrees that speakers should become the smart digital audio-processing devices of the future. Despite Creative Labs' product plans, it is interested in keeping the audio converter on a PC sound card and using analog amplifiers to talk to traditional passive speaker systems, said Micah Stroud, audio product marketing manager for the Americas.
"Digital speakers are a great solution-if everything is Dolby Digital," Stroud said. But "USB [as an interface to digital speakers] is not a dream picture." The real world, as he described it, includes diverse audio playback requirements including MPEG, RealAudio and WaveTable synthesis. "The digital speaker moves the cost of the sound card out to the speaker," said Stroud; moreover, he added, unlike a PC-based sound card a digital speaker is "a nonupgradable item."
That view is characteristic of a number of audio IC makers trying to hold on to design wins for processing done inside a PC. Still, it is a position that even Creative Labs-the father of PC audio with its SoundBlaster technology-has found hard to stick to.
The success of its Encore Dxr2 PC-based DVD player has encouraged the company to develop its own system for 5.1-channel Dolby Digital playback. The development also capitalizes on the miniature-speaker technology that Creative acquired with Cambridge Sound. Code-named Snowball, the Creative AC-3 player includes two electronic sections, one placed relatively close to the PC, the other residing within a separate powered subwoofer cabinet. The box close to the PC serves as a hub, gathering the analog inputs from a legacy sound card and/or the digital inputs from the DVD player or Sony-Philips Digital Interface source. The powered sub-woofer includes a full AC-3 decoder, D/A converters and power amplifiers for the subwoofer and five other connected speakers.
Overall, the new speaker systems from Philips, Altec Lansing and others-even an experimental audiophile speaker system constructed by Sony Electronics-point to an entirely different generation of audio components.
Digital speakers will demand new types of DSPs, data converters, audio power amplifiers and, to some extent, "virtualization" processors. Digital speaker systems, explained Altec Lansing's Freadman, require a digital interface to the console, a DSP, D/A converters and audio amplifiers-all within the speaker cabinet.
Specifically, the ADA 315 uses a DSP for Dolby Digital (AC-3) decoding and a pair of "side-firing" speakers in the left and right stereo speaker boxes to give left rear and right rear surround sound. A third box serves as a center channel and low-bass subwoofer.
Ordinarily, Dolby Digital Surround Sound decoding maps to six speakers (sometimes called 5.1 speakers): right front, left front, center front, right rear, left rear and a somewhat directionless low-frequency subwoofer. To play them to full effect, the user needs six speakers and amplifiers. But this can be too complicated for the average PC user, said Freadman, and too expensive for the new generation of sub-$1,000 PCs that will use the host CPU for DVD movie decoding. Here, separate speakers with built-in decoders and amplifiers will provide full surround-sound effects and offload this task from the host. The ADA 315, like the ADA 310 (a Sony-Philips Digital Interface system shown at Comdex), puts six speakers-along with all the decoding electronics, USB-connected audio DACs and miniature 10-W amplifiers (a 24-W amp for the subwoofer)-in a USB-connected three-box system.
RELATED ARTICLE:
The current generation of digital speakers use USB, with Class A-B amplifiers in small packages. But in future generations, said Freadman, the digital interface will look like 1394 or some kind of pulse-code used to modulate high-efficiency Class D switching amplifiers. "About the only part of the speaker that will remain analog," said Freadman, "is the diaphragm."
Just like the developers of audio sound chips and 3-D-sound processors, Altec Lansing sees PCs as home entertainment consoles. Unlike the developers who looked for ways to extend SoundBlaster compatibility to the PCI bus and enhance the game-playing experience on Windows 95 platforms, Altec and others see PCs as DVD movie-playback machines. While the inexpensive platforms will use the host CPU to decode DVD video (generally in an MPEG-2 format), the Dolby Digital audio will be decoded by a peripheral device far removed from the motherboard and its PCI bus.
DSPs in the speaker system will accommodate multichannel formats like Dolby Digital (AC-3). They will not necessarily promote 3-D "virtualization," said Freadman. Virtualization, or "3-D" audio, is a means of creating 3-D sound effects with just two stereo speakers. For example, head-related transfer function (HRTF) algorithms emulate human ear canals in the way they pick up sounds from different positions about the listener. In effect, the listener is tricked into hearing footsteps behind him (or bombs exploding overhead), when in fact all of the sound is produced by front speakers. Because of the need to produce dramatic effects with just two speakers, many of the virtualization algorithms developed by companies like QSound Labs Inc. (Calgary, B.C.), Spatializer Audio Laboratories, Inc. (Mountain View, Calif.), Aureal Semiconductor (Fremont, Calif.), EuPhonics Inc. (Boulder, Colo.) and SRS Labs Inc. (Irvine, Calif.) have their best utility with 3-D Windows games.
Dolby AC-3, in contrast, is a full 5.1-speaker surround sound, rather than an emulation. "Multichannel requires multiple channels," insisted Freadman. "We believe in delivering full multichannel sound to the user. Even if the sound is mixed down to two speakers, the AC-3 information is sent to the speakers." It is most convenient to download five-channel audio to the speaker system, then mix down to two, said Freadman.
Thus, the DSPs that will be used for this will probably not be PCI interface components like the Crystal Semiconductor (Austin, Texas) CS4610 SoundFusion PCI audio accelerator and CS4297 AC-97 codec combination. Nor will it be the ThunderBird 128, an audio accelerator chip developed by VLSI Technology (San Jose, Calif.) and Qsound Labs, or the SoundMax64, a development of Analog Devices (Norwood, Mass.) and EuPhonics. Rather, they may be more general-purpose programmable parts like the DSP56362 from Motorola's Semiconductor Products Sector (Austin, Texas) or the ZR38600 by Zoran (Santa Clara, Calif.). The latter, said Zoran's Paul Goldberg, audio products vice president, is the engine behind Altec Lansing's side-firing 310 and 315 digital speakers.
These 24-bit fixed-point devices have displaced 16-bit devices once used for audio signal processing. But even the 24-bit models may not provide the precision, dynamic range and interface-juggling capability demanded for next-generation audio systems, said Maria Tagliaferro, DSP product marketing manager at Analog Devices. "I think 24 bits is a dying architecture," she said. Her company has produced a $10 version of its 32-bit Sharc processor, which it believes will steal audio slots from other general-purpose DSPs. It is likely, though, that this area will drift toward custom or special-purpose DSPs. For example, Crystal Semiconductor's CS4926 standalone processor is targeting home theater with Dolby AC-3 and Digital Theatre Systems (Westlake Village, Calif.) decoding algorithms in hardware.
Noting this trend toward out-of-box processing, Medianix Semiconductor (Mountain View, Calif.) has developed a series of proprietary 24-bit DSPs that sit in the pathway between host-PC, standalone DVD player, stereo entertainment console or system.
The current generation of Medianix processors, like the MED25006 used in the MediaTheater speaker system developed by Boston Acoustics (Peabody, Mass.), decode Dolby Pro Logic. Upcoming versions of the Medianix DSP will employ Dolby Digital decoding with either full six-speaker surround sound or a virtualized field with two speakers. The MED25201, for example, is a full six-channel Dolby Digital (AC-3) decoder and a version of this device-the MED25202-will decode AC-3 but virtualize it for two speakers.
In fact, the company has alliances with the major algorithm developers including Dolby Laboratories, Harmon Interactive Group, SRS Labs and Spatializer Audio Labs.
These devices can take a variety of input formats, said a senior product marketing manager, but outside of the PC, it will not likely be AC-97.
Copyright 1998 CMP Media Inc.