On-board Audio Quality & Performance

When we first introduced this section into our motherboard roundups we focused almost exclusively on performance. We did some rudimentary verifications of audio output quality but there was nothing serious at all. Armed with RightMark's Audio Analyzer we were able to perform some more objective tests on the audio output quality of these on-board audio codecs.


The Audio Analyzer hardware setup

The way Audio Analyzer works is simple; you run a cable from the output of the sound device being measured and run it into the input of either the same device or a separate sound card. Sounds are then played from the device being tested and recorded at the same time; the signals are then compared and analyzed with their differences being summed up through a number of performance scores. The test obviously depends on the recording equipment just as much as the playback device so in order to keep things on a level playing field all of our recording was done using a SB Audigy; it's not the highest end card in the world but it provides a good reference point.

The only boards to be omitted from this test were the ABIT KX7-333 (because it has no on-board audio), the DFI AD76 RAID (because audio wasn't working properly in the preproduction BIOS) and the Soyo KT333 Dragon Ultra (because the board would not POST with our Audigy installed).

Audio Analyzer outputs ratings in six separate categories rating the output quality of the signal that is played back using the audio device being tested. The ratings range from Very Poor, Poor, Average, Good, Very Good and finally Excellent; the higher the rating the better. We won't get into too deep of an explanation behind these terms but here's what to look for:

Frequency Response - audio occurs at various frequencies (the human ear can perceive frequencies from 20Hz up to 20kHz), the frequency response of the audio device determines what frequencies can be accurately reproduced and what frequencies will be lost or reduced in volume. Generally the higher and lower frequencies are the ones that suffer the most, so an above average frequency response curve would be relatively flat from start to finish.

Dynamic Range - this gives you an idea of how well weak signals will be reproduced.

THD - Total Harmonic Distortion is best explained by the folks at RightMark:

"THD (total harmonic distortion) is a level of (usually unwanted) harmonics generated in the sound device. Usually high quality devices have a low THD value (lower than 0.002%), but there are exceptions. Many tube devices have rather high THD level, which makes their sound “warm”. But transistor devices must have low THD, because their (odd) harmonics don’t make the sound pleasant. "

The Noise level and Stereo crosstalk ratings should be fairly self explanatory.

Audio Output Quality Comparison
 
Frequency response (from 40 Hz to 15 kHz)
Noise level
Dynamic range
THD
IMD
Stereo crosstalk
ABIT AT7
Average
Good
Good
Very Good
Poor
Excellent
ASUS A7V333
Poor
Good
Good
Average
Very Poor
Very Good
ECS K7VTA3
Good
Good
Good
Very Good
Good
Very Good
EPoX 8K3A+
Good
Very Poor
Very Poor
Good
Poor
Poor
Gigabyte GA-7VRXP
Good
Good
Good
Very Good
Average
Very Good
MSI KT3 Ultra
Good
Average
Average
Very Good
Poor
Good
Shuttle AK35GT2/R
Poor
Good
Average
Average
Very Poor
Very Good

What's interesting to note here is that implementation as well as the specific codec itself greatly control the quality of the output. For example, the ABIT AT7 and the EPoX 8K3A+ use the same ALC650 codec yet they have dramatically different output characteristics.

It's interesting to note that the motherboard with the best output quality was the ECS K7VTA3 that used the older ALC201A codec. Obviously we don't have enough information to judge whether this superiority is caused by the codec or by ECS' engineering team, but it's an interesting observation nonetheless.

Overall Motherboard Performance Onboard Audio Performance

Log in

Don't have an account? Sign up now