EPIA MII 12000 Review

Posted on May 18, 2004

Jump to: Introduction The Nehemiah C3 CLE266 Chipset Box and Drivers Cardbus and Back Panel Board Connectors BIOS Settings Cooling & Power VGA & TV Output Benchmarking Details Sandra Benchmarks More Benchmarks AES Benchmarks Video Playback Audio Quality Conclusion

Measuring Audio Quality

We chose RightMark Audio Analyzer 5.0 to conduct signal analysis of the EPIA MII 12000, then for occasional comparison using a SoundBlaster Live! card plugged into the PCI port of the EPIA. We would have liked to have used an Audigy but alas, we don't have one.

RightMark Audio Analyzer works by playing known test signals through the output of a soundcard, and recording it at the input of the same soundcard. By comparing these two signals, it spits out results for Frequency Response, Noise Level, Dynamic Range, Total Harmonic Distortion & Noise (THD+N), Intermodulation Distortion (IMD), and Stereo Crosstalk. And nice graphs.

Frequency Response

Frequency response is the measure of signal level as frequency varies. A perfect graph would be flat at 0dB for all frequencies, but in practice most human ears are sensitive in the 40Hz - 15kHz range, and are sensitive to about 1dB, so +/-0.5dB variations are acceptable. In all the graphs, the MII 12000 is shown in white, and the MII 10000 shown in green.

The EPIA MII had a smooth response curves, unwavering up into the realm of dogs and cats, and in the lower end becoming responsive to -1dB at about 25Hz, even better than the M10000 we tested a year ago. This may have been due to slight test differences, but is impressive nonetheless.

Noise Level and Dynamic Range

The Noise Level test estimates the level of noise in a silent system, i.e. when no audio is present. Lower figures here are better. The Dynamic Range test applies a low-level signal at -60dB and estimates the linearity (which is very important for high-quality sound recording and playback). VIA claims the Six-TRAC audio codec used on the EPIA M and MII can achieve a signal-to-noise ratio of 97 dB when used on a sound card, and 90 dB in the noisier environment of a motherboard.

The MII 12000 measured a Noise Level of -93.5 dBA, and a Dynamic Range of 93.1 dBA. These compare to figures of -91.5 dBA and 91.0 dBA for the EPIA M 10000, and -85.3 dBA and 84.9 dBA for our ageing Soundblaster. It appears the VIA have managed to slightly lower the noise floor and increase the dynamic range of the MII beyond the already respectable figures of the EPIA M. This could have been achieved (even inadvertently) by different placement of components such as amplifiers and capacitors on the MII motherboard.

Total Harmonic Distortion and Intermodulation Distortion

The Total Harmonic Distortion (THD) of a system is measured by passing a 1kHz sine wave through the test chain at almost maximal amplitude and measuring the amount of distortions present at even and odd harmonics (multiples of the original signal frequency) of the sine wave. The figure is given as a percentage - the ratio of the geometric total of all these harmonics to the power of the test signal. But this figure alone does not paint a full picture - "even" harmonic distortions generally sound warmer than the less desirable harsh sounding "odd" harmonics. This is why tube amplifiers can have a high THD and still sound warmer and more "musical" than a transistor based amplifier with a lower THD. This test shows distortions caused by a test tone.

Intermodulation Distortion is a more complex test, measured with two test tones (usually 15kHz and 16kHz), that shows how multiple frequencies interact with each other. An ideal result on a frequency analyser would show just the two signals as peaks above the noise floor, but in practice artefacts are produced at ratios of the original signal. This test shows distortions that aren't present in the original test tone.

The MII 120000 measured a Total Harmonic Distortion of 0.021% and Intermodulation Distortion of 0.124%. These are perfectly acceptable results, comparable to current soundcards.

This is a typical THD spectrum plot we took a while back using an EPIA 800. We've marked some areas by way of explanation. Point "2" shows the 1kHz test signal. Point "3" are the first and second odd harmonics, at 3kHz and 5kHz. Point "4" are the first two even harmonics, at 2kHz and 4kHz. Point "1" is interesting anomaly - quite a large bump at 50Hz. Our loopback cable was crossing the power cord and picking up interference from our 50Hz mains power (we moved the cable and tried again...)

Stereo Crosstalk

Crosstalk tests how much signal energy bleeds from one channel into the other. A test tone is played in one channel, whilst the other muted channel is measured to see how much crosstalk occurs. The test is repeated with the channels reversed.

The EPIA MII was much improved over the EPIA M we tested previously, allowing less signal to bleed between the left and right channels - it gave us a Stereo Crosstalk value of -89.1 dBA.

Multichannel audio on the EPIA Ms

VIA's "Smart 5.1" allows the Mic, Line In and Line Out jacks on a motherboard be utilised as 6 channel surround sound audio outputs i.e. Front L/R, Rear L/R and Centre/Subwoofer. If you only have 2 channel audio content, you can enable "Magic 5.1" to simulate 6 channel audio (found in the volume control panel under rear speaker/advanced). If by contrast you have 6 channel audio content to playback, but only 2 speakers, you can use "DUALMAX" to down-mix the audio in hardware.

Audio Listening Tests

We conducted extensive A/B Comparisons with a Pioneer 454 DVD and the MII 12000, using the same stereo MP3 source material. We borrowed the use of a high quality Yamaha amp and B&W speaker system for the task. Our conclusion was that the standalone Pioneer had slightly more sub-bass presence and stereo imaging, but there wasn't much in it - we could only determine this after repeated listens. The Pioneer also had the advantage of a digital cable.

Conclusion -->