Q. My question may sound stupid, because I’m just a beginner in audio/video. Do I need to buy a DVD player with a built-in Dolby Digital dts 5.1-channel decoder? And if so, must I also buy an A/V receiver with a built-in Dolby Digital/dts decoder? Or would this be redundant? â€” G. F.
A.There is no such thing as a stupid question when you’re trying to ‘decode’ audio! No, you don’t need a DVD player with a built-in Dolby Digital/dts decoder because virtually all modern A/V surround sound receivers already have internal Dolby Digital/dts decoders. The DVD player just needs to pass the Dolby Digital or dts data stream to the receiver via a coaxial or digital optical cable, and even the least expensive DVD players will do that. So it would be redundant to get a DVD player with built-in decoders (there is an exception: see below).
DVD players with built-in decoders are for use with older equipment that wonâ€™t decode the digital 5.1-channel surround formats. For example, you might have a couple of old stereo amplifiers (or an old Dolby Pro Logic receiver) you wanted to use in an inexpensive Dolby Digital 5.1-channel home theater setup. As long as your old amps or receiver have line-level inputs for each amplifier channel, you could cobble together enough amps to feed the front left and right, center, and two surround channels. The DVD player with the built-in decoder will have six analog output jacks, one for each channel. Then youâ€™d need to add a powered subwoofer for the “.1″ low-frequency effects channel. Youâ€™d use the DVD playerâ€™s internal menu to do the proper setup for your speakers. It would be inconvenient adjusting overall volume levels, but it would work, and youâ€™d save the cost of a new Dolby Digital/dts A/V receiver.
But if you want playback of DVD-Audio or SACD multichannel audio discs, the DVD player must have a built-in decoder for these formats because there are no receivers that will decode them (the record labels fear digital piracy so they wonâ€™t provide digital outputs). Such DVD players almost always include Dolby Digital dts decoders as well.