Enter the Mini-ITX.com online store


September 05, 2017
Choosing the right DC-DC PSU

August 27, 2015
AMD's Project Quantum

August 13, 2015
The Redstone PC is the ultimate Mini-ITX Minecraft Machine

October 09, 2014
The "Restomod TV"

April 09, 2013
Installing NAS4Free

February 28, 2013
Building an XBMC 12 Home Theatre PC

January 25, 2011
XBMC Guide updated to version 10.0

August 06, 2010
Building a Green PC

February 15, 2010
Building an ION powered HTPC with XBMC

October 10, 2008
The "Cambridge Autonomous Underwater Vehicle 2008"

Mini-ITX Online Store

September 12, 2008
"Florian", the DVD burning robot

September 05, 2008
The "i-EPIA"

May 22, 2008
The "GTA-PC"

April 14, 2007
The "Digg" Case

January 19, 2007
The "ITX-Laptop"

December 07, 2006
The "Tortoise Beetle"

October 02, 2006
The "DOS Head Unit"

August 31, 2006
The "Janus Project"

August 05, 2006
The "Leela PC"

June 26, 2006
Nano-ITX in a Football

May 17, 2006
The "EPIA Alloy Mod"

April 11, 2006
Neatorama's Collection of Case Mods

February 18, 2006
The "Rundfunker"

October 24, 2005
The "ITX TV"

October 06, 2005
The K'nex-ITX

August 05, 2005
The "Waffle Iron PC"

July 21, 2005
The "Supra-Server"

July 18, 2005
The "Mega-ITX"

July 07, 2005
The "Encyclomedia"

May 25, 2005
The "Accordion ITX"

Mini-ITX Online Store

May 16, 2005
The "FileServerRouterSwitch"

May 15, 2005
The "Mini Falcon"

May 13, 2005
The "Bender PC"

May 11, 2005

May 10, 2005
The "Frame"

April 20, 2005
The "Jeannie"

March 09, 2005
The "Cool Cube"

January 30, 2005
First Nano-ITX Project?

January 17, 2005
The "iGrill"

January 15, 2005
The "Gumball PC"

December 15, 2004
The "Deco Box"

December 03, 2004

October 06, 2004
The "Coealacanth-PC"

September 17, 2004
The "Gramaphone-ITX-HD"

August 26, 2004
The "C1541 Disk Drive ITX"

August 25, 2004

August 13, 2004
The "Quiet Cubid"

August 06, 2004

July 14, 2004
The "Moo Cow Moo"

July 02, 2004
The "Mini Mesh Box"

Full alphabetical archive on right hand side of page...

Nehemiah M10000 Review
Posted on May 19, 2003

Measuring Audio Quality

We chose RightMark Audio Analyzer 5.0 to conduct signal analysis of the Nehemiah, comparing it to an EPIA 800. Classic EPIA results were almost identical, as were other EPIA M results, so these have been omitted for clarity. This is to be expected - the Classic EPIAs all use the VT1612A audio codec, whereas the EPIA Ms all use the newer VT1616 audio codec. The boards also have different layouts - important as the placement of components such as amplifiers and capacitors can affect audio quality.

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 Nehemiah is shown in white, and the EPIA 800 shown in green.

Frequency Response

Both boards have smooth response curves, with the Nehemiah showing more bass welly in comparison to the EPIA 800, becoming responsive to -1dB at about 40Hz against about 120Hz. Both boards had excellent top-end response, although the Nehemiah stays flatter, for longer.

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. We inverted the graph here for clarity, as lower figures 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).

Noise Level and Dynamic Range

The Nehemiah clearly has lower noise floor and a bigger dynamic range than the EPIA 800. VIA claims the Six-TRAC audio codec used in the Nehemiah 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.

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.

Total Harmonic Distortion and Intermodulation Distortion

Both the EPIA and EPIA M have similar THD and IMD levels. Compared to current soundcards, their THD is good, and their IMD is acceptable.

Total Harmonic Distortion - EPIA 800 with power cable spike

This is a typical THD spectrum plot. 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 ran the test 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. We inverted the graph here again for clarity, as lower dB figures are better.

Stereo Crosstalk

This time the EPIA 800 fared better, allowing less signal to bleed between the left and right channels. In theory this should give it a better stereo image, though in practice both results are good.

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 Nehemiah, 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. In our speaker tests, the EPIA 800 gave a solid performance, perhaps lacking slightly in the low-end welly that the EPIA M and standalone DVD player had.

We next tried playing back some AC3 content using the S/PDIF port. Both boards gave similar audio results to before, although the EPIA 800 didn't have the processing power to smoothly playback the accompanying video.

Finally, we listened to material on the Nehemiah and the 800 through a pair of high quality Beyerdynamic DT531s headphones. This time, the difference was marked - the EPIA M had a bass presence and clarity that the 800 simply couldn't match. By comparison the 800 was thin and harsh sounding. The M10000 also had much more volume available on the headphone socket - we had to turn it down slightly.

Benchmarks - Setup Details -->

Board Finder
Case Finder
Mini PC Finder