Hi-Res Audio for the New Hi-Def DVD Formats – Standard DVD audio was complicated enough for the uninitiated: Many discs used only Dolby Digital mono or stereo. Then there might be a separate uncompressed PCM track, and also a DTS track. The Dolby and DTS options might also have 5.1 surround versions. Lately many standard DVDs didn’t even have a menu to select audio options, but automatically selected them based on what was hooked up to the player’s outputs.
Now with Blu-ray and HD DVD many consumers are becoming totally baffled. Standard Dolby Digital and DTS use higher sampling rates for improved sound but are still decodable with the player or AV processor’s existing circuitry. Many Blu-ray discs (not HD DVD) feature uncompressed 5.1-channel PCM – which is output via the same six-channel analog cables as the output of SACD/DVD-A players. Especially at 96K/24-bit this is the last word in hi-res surround and the closest match to the source tracks in the movie studio. The clarity, transparency, and dynamic range is without equal. Since there is no data reduction, these PCM tracks take up a lot of space, but then Blu-ray has a 50 GB capacity, so there’s no problem. With a bow toward better fidelity and less requirement for extreme data reduction, Dolby and DTS both have their new so-called lossless codecs which are standard on HD DVD discs but only optional on Blu-rays. Dolby True HD and DTS-HD have higher bitrates and up to 7.1 channels of surround. They are supposed to match the master bit for bit, and they can be encoded at either 24 or 16 bit. They can be carried along with the video on an HDMI cable. But you have to have a player or processor to decode them, and earlier Blu-ray players lacked that. Some sound mixers and designers feel even though they are considered lossless, the uncompressed PCM 5.1 tracks are superior. We agree. [Now if we could just get studios to stop offering Dolby rather than uncompressed PCM on mono or stereo tracks of any DVDs…]
Consumer Warning on Electronic Products for Children – The National Association of State Fire Marshals have issued a consumer warning on two models of Chinese-made electronic products used by children. Preliminary testings suggests a potentially serious fire hazard due to highly flammable outer plastic enclosures. Precautions include the following: Keep all candles away from the plastic outer enclosure; before purchase read the literature on the product to determine if it meeds the standard Underwriters Laboratory 94 V-1 or better, and the International Electrotechnical Commission’s spec IEC TS 62441 or equivalent. Consumers are advised to be careful with open flames around all computer-related equipment, speakers, and ink-jet printers.
