Asus HDAV 1.3 Slim Review: Bitstream for the Masses?
The HDAV 1.3 Slim
The downside for most HTPC setups is the handling of high definition audio content. Up until this point, the best we could expect was 8 channel LPCM over HDMI from the Intel and NVIDIA chipsets, as well as the AMD HD 4000 series of video cards. Current AMD chipsets and the older HD 2000 and 3000 graphics cards only support 2 channel LPCM. 8 channel LPCM certainly is not a bad thing, but it is not bitstream accurate audio when dealing with HD formats such as Dolby TrueHD and DTS-HD Master Audio. While the audible difference to between 8 channel LPCM and a bitstreamed content may be minimal at best, people who buy a high end receiver with specialized hardware decoders are not fond of the thought of their $99 BD playback software converting the HD formats into 8 channel LPCM. If 8 channel LPCM is not an option, then most movies fall back on DVD quality encoding, such as Dolby Digital 5.1 and DTS.
Not a whole lot of padding in there, but the box is thick enough to absorb shock when needed.
While the latest AMD Radeon HD 5800 series of cards now support bitstreaming, they are a bit overkill for a HTPC. These are big cards with heavy power consumption while under load. They are also quite a bit more expensive as compared to just an integrated motherboard. With NVIDIA not willing to produce an updated chipset for the AMD market (and is questionable about continuing in the Intel market), we still have quite a few months before AMD’s latest chipset offerings with bitstream support will be available. The other alternative is the G45 chipset from Intel, but it again is limited to 8 channel LPCM at max, and is not as competent at HD video playback as the AMD and NVIDIA parts.
The latest AMD HD 5700 series of cards also support bitstreaming, but as of this writing I do not believe any 3rd party BD playback software supports that functionality. These cards are a lot more affordable than the HD 5800 series, and the HD 5750 certainly looks to be hitting the sweet spot for both playback of video and audio. Again, software compatibility for the full functionality is currently missing.
For the time being there really are four options for HTPC enthusiasts to enable bitstreaming: three sound cards from Asus and one from Auzentech. Of those cards, only one is half height, so it can fit in low profile HTPC cases. That is the product we are taking a look at today.
The HDAV 1.3 Slim
Some time ago Asus essentially bought exclusive rights to the C-Media CMI-8788 chip. They then rebranded the chip the Asus AV200. The chip can handle 24 bit/ 192 kHz audio, as well as be able to encode on the fly Dolby Digital 5.1 and DTS. The chip does not encompass as many gaming features as the Creative X-Fi does, but it still does support DirectSound3D and other formats. With the latest drivers from Asus though, it can emulate higher levels of EAX. Considering how few CPU cores most games actually utilize, the extra CPU cycles needed to emulate EAX 5.0 are more adequately put to use.
The contents are fair, and it has everything a user needs to get their HTPC set up with this card.
The 1.3 Slim was designed to fit in half height cases, and the bundle comes with the cut down backplate that would be needed in many of these cases. A few things had to be given up though. The big one is that there are no back panel analog audio connections. The only analog connection is for the case’s front panel connection. Happily it appears as though Asus did a nice job with components for the front panel audio. The codec, DACs/ADCs, and OPAMP used are all of good specification, and when headphones are connected to the front panel the quality is as good as anything else out there.
The half height card is packed full of chips. The two biggest ones are the HDMI receiver and transmitter. The HDAV 1.3 Slim is fully HDMI 1.3a compliant, and it offers the fully protected path required to play back High Definition video and audio content. The other large chip is of course the AV200, which is the overall controller for this board. The card is PCI 2.2 compliant, which is a bit of a step back from its bigger brothers which utilize PCI-E connectivity.