These days, when every mainboard comes with an integrated sound adapter, few manufacturers dare release discrete audio solutions. Many brands have left the market altogether, others have halted the development process and don’t care much about driver updates. That’s why every new device provokes a huge interest in the PC audio community. And when a new brand comes to market, it is a real sensation. A standalone sound card is supposed to be far superior to the integrated sound of mainboards. Otherwise, it makes no sense at all. Considering Creative’s monopoly on gaming technologies, the single argument in favor of a standalone sound card may be its quality of music playback. More exactly, it is the price-to-quality ratio because expensive components and a meticulously designed PCB make the end product too expensive whereas cheap components don’t yield the desired quality. The price also includes the cost of developing and updating the driver. Having weighed all the pros and cons, most manufactures preferred to avoid such an inconvenient product as a non-professional sound card, yet the niche doesn’t remain empty. The young and daring company Auzentech announced its arrival by releasing a few interesting products based on C-Media’s controllers. The X-Fi Prelude 7.1 brought an international success to the company. In 2007 another serious player stepped on the scene: the world-famous hardware manufacturer ASUS began to sell a pretentious audio solution for PCI and PCI Express buses.
As a matter of fact, ASUS is not really a newcomer in this market. Last century the company produced a PCI sound card called ASUS 3DexPlorer AXP-201. And some time previously, there was an audio-video combine for a special PCI/ISA slot installed on some of ASUS’ mainboards, e. g. ASUS T2P4. It was about ten years ago, and now the company makes a second attempt to establish its brand on the sound card market. Drawing on its earlier experience, ASUS puts its stake on wide functionality coupled with highest technical characteristics. The company chose a good strategic partner to quickly and cleverly solve the task. For the Taiwan-based C-Media Electronics the partnership with ASUS is surely an opportunity for further growth, so this collaboration is mutually beneficial.
January 2006, at a Las Vegas expo, C-Media introduced a number of interesting solutions, two of which pertain to the subject of this review: the PCI audio controller C-Media Oxygen HD, which equaled the widespread VIA Envy 24HT in its capabilities, and the digital sound processing software C-Media Hydrogen that provided support for DirectSound3D, licensed technologies from Dolby Laboratories, and a number of other features I’ll describe when I’ll be talking about the ASUS sound card.
The mixture of Oxygen and Hydrogen gave birth to a lot of sound cards from then-obscure firms such as Bluegears, Sondigo, HT Omega, Auzentech, and Razer. ASUS just couldn’t stay aside.
Let’s view the specs of the C-Media Oxygen HD in comparison with the VIA Envy 24HT.
| Envy24HT | Oxygen HD |
PCI interface | PCI 2.2 with bus mastering and burst modes |
Sample rate | up to 192 kHz |
Resolution | 24 bit | 32 bit |
Outgoing streams | 8 | 12 |
Ingoing streams | 4 | 8 |
I2S output pairs | 5 | 4 |
I2S input pairs | 4 | 4 |
S/PDIF transmitter | 192k/24-bit |
S/PDIF receiver | – | 192k/24-bit |
MPU-401 MIDI UART | 1 |
Both chips support programmable reassignment of the output channels and digital monitoring of the inputs. One of the five dual-channel I2S outputs of the Envy 24HT is assigned to the digital output equipped with an integrated transmitter, but allows connecting an additional device with an I2S interface. The Oxygen HD lacks this capability but features an integrated S/PDIF receiver whose signal can be sent directly to the digital output, which allows using the sound card as an adapter from the optical to coaxial cable and vice versa. The Envy 24HT can only record simultaneously from two stereo sources (usually, from the ADC and S/PDIF) whereas the Oxygen HD allows recoding from three sources at once (one is an eight-channel source). The sources can be flexibly selected from among the four input I2S pairs, integrated digital input and even two AC’97 codecs.
C-Media Oxygen HD Flowchart
Judging by the description, the chip is free from obvious weaknesses and can make a good foundation even for a professional sound card. But today I’m going to discuss a product intended for home use in a multimedia center or in a gaming PC.