The HTPC / Windows 7 Chronicles: You Asked, We Answer!

Amp Up: Using Maui’s Amp, Continued

One of the coolest aspects of getting the D2Audio sound device up and running is that it’s total cake, especially under Windows 7.

Because the amp is attached to the HD Audio bus, it uses Microsoft’s UAA driver and literally works immediately upon installing the operating system. You might need to open your sound properties and change the output device first (configure your speakers while you’re at it), but so long as the 5.1-channel card is connected to power and you aren’t shorting out speaker wires on that frustrating connector block, it’ll likely be good to go.

By default, there are a handful of enhancements available for modifying the sound (this is with the speakers configured for 5.1-channel output). The only one I wanted was Bass Management, which let me send everything under 80 Hz to my SVS subwoofer, rather than the LSi7 speakers. I immediately noticed that the bass levels were lower than what I was expecting. Adjusting the gain on the sub by a couple of notches fixed that, though.

So, What About Receiver-Class Functionality?

Here’s where I revisit the upcoming firmware update. According to D2Audio, the DAE-3 should be able to support sophisticated level correction, sound positioning, bass enhancement, and speaker virtualization. Much of this is what you’d expect out of a CE receiver, and it really hasn’t been exposed as of yet, despite the fact that this platform is coming up on its one-year anniversary. Take a look at the image below, though, and you’ll get a better idea of just how many attributes can be adjusted here.

D2Audio DAE-3 signal flow

I don’t have the firmware in-hand yet, and it sounds like there is some discussion about when/how the early-adopters who’ve already purchased this platform will get access to it, but clearly there are plans to improve upon the work that has already been done to make Maui a reality. AMD's Jay Taylor goes into more depth on this in his most recent blog post.

Real-World Performance

Of course, we can’t pass judgment over something that isn’t available yet, and so Maui’s capabilities need to be evaluated based on what’s out there now. I spent most of my time with music and movies, since those are the applications this HTPC would address.

But first, it was slightly disconcerting to hear, upon startup, my subwoofer make three loud thumps during the boot process. This is apparently a known issue, and there is an update planned that will hopefully keep the sub output muted through boot-up in order to prevent the issue. For now, you have to remember to either turn down the gain on your sub or turn the sub on once the OS is up.

With Windows 7 running, I started testing with music. Now, it wasn’t easy to do A/B comparisons, since getting sound out of the D2Audio configuration meant breaking down two conductors on each speaker wire, taking off the banana clips, and cramming them into the high-density block. However, I was able to compare the receiver’s output to the D2Audio analog output and then switch back to the receiver.

I hesitate to declare one solution better than the other, but they certainly produced different sound. The 5.1-channel analog output of the D2Audio amp actually sounded richer (despite being a Class D amp) and more bass-heavy in the satellites (despite an 80 Hz crossover setting). It required a lot more gain to get good bass from the subwoofer, though.

On the other hand, the Onkyo receiver (which was only outputting two channels via HDMI,) delivered what I thought to be superior bass management, albeit with a sound I can only describe as tinnier. Now, that’s not how you’d ever use this platform—in fact, if you wanted to go from an HTPC to an AVR, you probably wouldn’t look to Maui at all. Rather, Nvidia’s GeForce 9300 or Intel’s G45 would likely make better options. But we’ll get into the reasons why shortly.

Next up was movies. Using the latest version of PowerDVD 9 (with Avivo acceleration enabled and six-channel output specified), I played through Dark Knight and Transformers. For the most part, the same qualities observed while listening to music applied here, though in a less pronounced manner. Most noticeable was the loss of bass versus what I’m used to with the PS3. Of course, this is rectified by increasing gain on the sub.

More important here is the fact that “six-channel output” does not include the Dolby TrueHD or DTS-HD Master Audio formats included with most Blu-ray movies.  We’ll get into this on an upcoming page, as it was a specific question asked by a reader after the previous piece went live. 

The take-away is that yes, the D2Audio chip works. It works well. It sounds great. And I was able to get ample volume to fill a 10 x 10 theater room uncomfortably using four ohm speakers without any protest from the 450W power supply driving this setup. I don’t consider this solution completely ideal yet, due to the speaker block and the lack of a protected audio path. But the former can be worked around with a little creative engineering and the latter is under investigation by AMD, which believes that nothing stands in its way of enabling the latest audio formats, eventually.

Keep reading, though. I’m not done yet with the audio talk.

Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.