PROS / The output and input SNR is well above the standard.
CONS / The card does not have basic 3.5mm audio ports.
VERDICT / The audio performance and excellent APIs make this card ideal for experienced audio enthusiasts.
The ASUS Xonar Essence ST is quite impressive when it comes to overall performance. Signal-to-noise ratios (SNRs) give you a ballpark figure of the sound quality and tell you a lot about a sound card. Both the output and input SNRs are around 118 dB, which is very impressive when compared to many of the other sound cards on the market. The harmonic distortion is extremely low at only 0.0003 percent for its overall output and 0.0002 percent for input. The Total Harmonic Distortion (THD) numbers on the ASUS Xonar Essence ST make it able to produce a more accurate reproduction of sound no matter if you're using speakers or a headset. The sound card has a 2-volt regulator module, which helps keep the power flow in check.
The big plus that the ST has over much of the competition is the frequency response range. ASUS understands the need for a broad range, and their cards have some of the largest ranges on the market. Many cards simply meet the standard needs or are only slightly better. This ASUS card, however, covers the industry standard and more with response rates that range from 10Hz to 90kHz at 192kHz. It is important to get those lows low and the high highs because it makes for higher quality audio. This excellent range makes it easy for us to give the ASUS Xonar Essence ST our Top Ten Reviews Silver Award.
The signal-to-noise ratio helps reduce the amount of noise corruption or background noise you hear while listening to music or other audio. The ASUS Xonar Essence ST has one of the highest SNR and is able clear up the background noise of any audio signal. At 124 dB you will have no trouble with extra noise while listening to your favorite music or playing your favorite game. We were also very pleased with the low total harmonic distortion coming in around 0.003 percent for input and 0.0002 percent for output. These numbers translate into very little sound distortion, which is clears up any odd sound during recording. You will also find a wide frequency response range of 10 Hz to 90 kHz at 192 kHz. This large range lets you hear every note, as they should be heard.
Sample Rate and Resolution
Sample rates and resolutions on the ASUS Xonar Essence ST fall in on the high end across the board – with a 24-bit sample rate and resolution of 192kHz. Overall we are pleased with the sample rates and resolutions on this sound card. The high sample rate is complemented by the even higher frequency resolution. The end result is a sound that is noticeably better than the one you'll get with most competitors.
The ASUS Xonar Essence ST has a very similar I/O port layout to the one you will find on many other ASUS sound cards. The card is ideal for surround sound home theater systems since it is one of the few cards that comes with built-in 6.3mm output and input ports. You will also find an input and output RCA port and a combination optical and coaxial port. You will need an adaptor for the 3.5mm port, but the adapter is included with your purchase. We would like to have seen the 3.55mm port come standard since most people are very used to using this type of audio port. However, for the professional audio enthusiast, the additional ports will come in handy and will make sound production that much easier. Overall, we are pleased with the variety of I/O ports found on the ASUS Xonar Essence ST.
The primary difference between this card and many of the others we reviewed is the interface type. Instead of going with the new and improved PCI Express interface, ASUS decided to stick with the standard PCI interface for this sound card. Many will argue that the older interface has advantages, but in the long run PCI Express is becoming the standard for most motherboards. While most motherboards currently have at least one PCI slot, the technology is somewhat outdated and is not able to handle the same transfer rates as PCI Express. You will want to make sure your motherboard has a PCI slot and that it's spaced out enough from your video cards before making any final decisions.
The processor in this card is the ASUS AV100, which packs plenty of power, enough to ensure the best possible sound from this card. The ASUS Xonar Essence ST has one major advantage; it is capable of utilizing the high fidelity Xonar H6 multi-channel extension board, which provides a signal-to-noise ratio of 120 dB. This one addition will greatly improve your surround sound experience when used with a fully set up 7.1 surround sound system.
API Compliant Standards
One really nice thing about this sound card is the fact that it has support for most of the base APIs. It doesn't include some of the newer more extensive ones, like Dolby Digital EX and DTS-ES, but still covers more than most of the other cards we reviewed. It also has three main 3D audio positioning sound libraries, OpenAL, DirectSound and A3D. These are mostly used for gaming and help you hear what direction things are coming from, giving gamers an advantage over their opponents. Additional APIs, like DirectSound, Dolby Headphone, Digital Live and many others, will also help with gaming, recording or simply listening to music.
The ASUS Xonar Essence ST is one of the best cards on the market. The use of older PCI technology is the only major drawback, since down the road most motherboards will likely not have a slot for this sound card. However, we are pleased to find so many base APIs, and are more than satisfied with the high sample rates and resolutions. When it comes to overall sound quality, the ASUS Xonar Essence ST is a huge contender and a solid choice for any audio enthusiast. This is the safe-bet sound card that is compatible with almost everything.