X-bit labs

Contemporary Integrated Sound Solutions: Storm is Coming (page 6)

Category: Multimedia

by Sergey Samarin

[ 08/25/2003 | 03:57 PM ]

ASUS A7N8X back panel

The audio subsystem of A7N8X is a mosaic of an APU, SoundStorm/Dolby Digital Encoder and six-channel Realtek ALC650 codec. Buying the mainboard with SoundStorm, the user will find the following additional connectors at the back panel:

• Six-channel analog output;
• Microphone-in;
• Line-in;
• Digital S/PDIF output.

As you see, the A7N8X mainboard carries all of them at its own back panel. There are also mainboards that come with brackets for the extra audio connectors.

Now, let’s try to make it clear what the audio processor is on the hardware level. Here is the APU flowchart:

APU flow-chart

So, the nForce2 APU consists of four sections:

• Setup Engine;
• Voice Processor;
• Global Processor;
• Dolby Interactive Content Encoder (DICE).

I guess the purpose of at least three sections is evident. Let’s dwell on the last one aka DICE. Encoding into the Dolby Digital format is no mystery, in fact. All film studios do it when recording soundtracks for movies we watch in cinema houses or in the home DVD-theater. However, software processing of this content as performed by various players consumes a lot of system resources. Moreover, Dolby Digital audio should be “pre-prepared” to be reproduced along with the video. When CPU resources are insufficient, you will have the sound lagging behind the picture: that’s the tradeoff of the software processing. So, that’s where the word “interactive” in DICE comes up. Roughly speaking, this APU section is responsible for fetching “on the fly” the digital stream during DVD playback, converting it into Dolby Digital 5.1 format and outputting through the digital S/PDIF output onto an external hardware decoder. Here, the APU from NVIDIA is much more powerful than Audigy2 from Creative. The audio card cannot yet decode Dolby Digital in real time and only pre-encodes this digital content.

We may assume that such a multi-functional integrated audio-subsystem from NVIDIA should have a flexible and detailed control panel. The manufacturer tried to make it up to the mark, by taking advantage of the positive experience other companies had collected in this field. The Control Panel is a well-done product; it is informative, offers fine-tuning options to set up the system according to your own needs.