Summary: Boasting a 124dB signal-to-noise ratio, a built-in headphone amp delivering 600ohms of impendence with <0.001% distortion, swappable OPAmp socket, and Nichicon "Fine Gold" capacitors, the ASUS Xonar Essence is designed for audio purists who want the best audio quality possible. But does the card live up to its specs? See how the card performs in this review!
Asus began with their Xonar line of audio cards, each one designed for a specific market, from gaming to home theatres. Asus is also one of the only manufacturers designing cards that use x1 PCI-Express slots, which have been woefully underutilized since their inception 5 years ago. One of their newest cards is the Xonar Essence STX, which is being billed as a sound card for the audiophile. Featuring individual pre-amplifiers for each connection and an interchangeable op-amp, the Essence STX has some pretty impressive specifications that help gear it up to take on the most discerning audio user.
As the Essence is designed more for audio fidelity than gaming, Asus implemented 2-channel RCA connectors as well a 6.3mm stereo jacks for the headphone and microphone connectivity. The Coaxial/TOSLink combination connector supports both S/PDIF and Optical output. Internally, the Essence supports front panel audio via a standard 9-pin connection. This allows you to connect your casesí front panel audio ports to the Essence without the need for any extra equipment. Due to the hi-powered amplifiers utilized on the board, the Essence requires extra power in the form of a 4-pin molex connector from the power supply.
Here we can see the op-amp, which comes in a standard 741-type 8-pin package. There are a variety of operational amplifiers available on the market and this allows the Essence to be customized to just about any userís particular taste. Generally speaking, the op-amp is what helps to provide the Ďcolorí of the sound produced. Audio purists know that by changing out the op-amp, you can adjust the brightness and color of the sound to satisfy their particular needs. By including an op-amp that is easily changed out, Asus has demonstrated they understand what the audiophile is looking for in a sound card.
The pre-amps for the headphone, microphone, and RCA jacks are all housed under the EMI during normal operation. This allows the very sensitive components to operate with as little electronic noise as possible.
Asus also did not implement a jack detect function, so if you plug headphones into either the back or front panel, you have to manually swap the output. They did, however, include a function for increasing the headphone gain from 0 to +18dB, allowing the user to make maximum use of their high-end cans.
The usefulness of other features in the Asus drive could be debated, like the VocalFX voice changer. The software allows the user to alter the sound of either recorded voice or for VOIP applications. While this could prove useful should you wish to make any ransom demands, in practice, we doubt the function will be used beyond the initial 10 minute period you own the card. The Essence also supports a karaoke function which automatically shifts the level of recorded music, allowing everyone to become a drunken businessman should their hearts desire it. If the Essence ends up in a HTPC, then we imagine this function could make for some unintentionally hilarious parties.
One of the more interesting features is the inclusion of Dolby Digital Live!, a real-time encoding scheme that takes any audio signal and turns it into 5.1 surround that is output through the optical connector. This makes the Essence perfect for both gaming and home theatre PCís, given that it can easily connect to any standard receiver and output Dolby Digital surround. Asus is hardly the first card to include DDL as a feature as both Realtek and Creative offer it on certain boards. However, being that on-board audio is notorious for high noise levels and Creative requires you to purchase the DDL package separate from their cards, it goes to Asusí credit that they would include it inherently. By utilizing DDL, the Essence STX stands to be a fairly complete audio solution, whether itĎs application is music, movies, games or a mix of all three.
AMD Athlon 5000+ Black Edition
HIS Radeon 4870X2
4GB OCZ Reaper DDR2 1066Mhz
Western Digital 300GB SATAII
Lite-On LH201AS DVDRW
Realtek HD Audio ALC889A
Creative X-Fi Fatal1ty
Asus Xonar Essence STX
Logitech Z-5500 5.1 Surround System
Windows XP SP3
Windows Vista 64-bit SP1
We also ran a series of benchmarks in some of the latest game releases to test the processing capabilities of the Essence in comparison to other popular audio solutions, namely integrated on-board audio and the X-Fi Fatal1ty from Creative. Our goal with these tests was to see if the Essence was up to par with current offerings and what, if any, effect on frame rate it could have.
Our RMAA tests were only run in Windows XP due to a compatibility issue between the program and Vista. Our gaming results were tested in both operating systems to see what difference we could see.
In fact, the Essence boasts better numbers than both our other solutions tested. The Essence saw lower crosstalk and noise levels, as well a greater dynamic range. The low total harmonic distortion guarantees accurate audio reproduction whether it is in music or movies. When you have a high THD level, the signal can be altered by harmonics added from surrounding electronic components.
The frequency response graphs continue to show how well designed the Essence is. When looking at a frequency response graph, you want to see as flat a line as possible. This represents the ability of the amplifier to produce certain frequency tones within a specific decibel level. You want a constant volume throughout all the audible frequencies. Otherwise, it creates a jarring listening experience depending on the sounds being played.
As you can see above, both the Essence and Realtek cards gave a good showing at 16-bit, maintaining a fairly constant level throughout the test. At 24-bit, the Essence pulled ahead as neither the Fatali1ty or Realtek solutions were able to play frequencies above 20kHz, as shown by the drop-off. However, as you can see in the graph, the accuracy of the Essence seemed to drop off itself once it got above the 20kHz range, which is not something you want to see when the card is being billed as Ďreference quality.í The Essence had a hard time keeping the volume levels within 1dB as the frequency increased.
The X-Fiís results were all over the place throughout all our frequency response tests. We tried tweaking the driver options, but we always saw the same result. Even following Creativeís guidelines for testing with RMAA did not give us different results. We are left to conclude that something must be happening either at the driver or hardware level that is altering the test results, but we were unable to find any answers as to what that was.
Fallout 3, Far Cry 2, Call of Duty: World at War