The control pod of the Z-5500 Digital Speaker system contains a decoder that will interpret audio signals encoded in specific digital formats. These formats are Dolby Digital and DTS 5.1 .The encoder does not work with HD audio coding formats usually found on HD DVD's and Blu-Ray DVD's.
The encoder on the control pod works with "raw" digital data. If the audio signal is already decoded by your sound card or DVD player for example, the Z-5500 decoder cannot interpret this now non-digital signal. The control pod will display "No Digital Data".
The decoder in the Z-5500 control pod will work with digital data from a stereo source such as MP3's played through a Sound Card that has a Dolby Digital encoder, or a DVD player using media that is not encoded in a digital format. The MP3 file will play through the Sound Card and be encoded as "raw" or "bitstream" and the Z-5500 decoder will interpret that digital data as Dolby PL II Music, and in the case of a DVD, Dolby PL II Movie. This will not deliver true 5.1 Surround Sound, but an approximation based on frequency filtering. If the Sound Card does not have an encoder, the control pod will display "No Digital Data".
NOTE: This article also applies to all 5.1 Digital Speaker Systems, including the Z-5500, Z-5450, Z-5400 and Z-680.