Microsoft Audio 4.0 - Normal Quality Level

The newest entry into the field of audio compression, MS Audio 4 is actually targeted at the streaming market just as Real Networks G2 technology. The difference is that Microsoft has put audio quality at a higher priority than Real. It is generally accepted that G2 has better video quality and that MS Audio 4 has better audio quality. While this encoder is not the most suited for the home user (ranking with Real and TwinVQ in this respect) the Winamp plugin for Windows media allows the output of the player to be directly encoded into a MS Audio 4 file. This is a very nice feature indeed.

Windows Media Encoder

Microsoft has made quite a show of this technology. MS funded testing by NSTL seems to suggest that MS Audio at 64 kbps has more quality than MP3 at 128 kbps. As far as our ears tell us, this is not so. I am not really sure what the music they tested on and what sort of hearing capability the listeners in that test had. Of course, the fact that they had 77 listeners to our 3 would mean I can't write it off. But everyone I have tortured into sitting and listening to encoded and non encoded music agrees that MS Audio is definitely not THAT good. Did I emphasize the 'that'? Before I go on, I would also like to point out that the MP3 encoding in the comparison page at Microsoft have been encoded with Joint Stereo disabled. This is a very important feature in compressing stereo music and newer technologies such as AAC use it. This is quite a big issue at the bitrates in question (up to 128 kbps). Also I do not understand why they think that MP3s don't go higher than 128 kbps. Anyway enough of that.

Observations

(If you have a problem downloading these files right click on them and select save as. You can rename them to have the extension .WMA to playback with Winamp)

Very crisp sounding music is a feature of this compression or maybe the player. I say "maybe the player" because the sound seems to remind me of what you get when you lower the tones and up the treble and bass of a EQ. It is possible that the play back routines do this. When listening to Dire Straits, a extra listener I had brought in to get another opinion on commented that the encoded file sounded better than the original! Well, except for that annoying after sound you get from a sharp sound. The sieve like sound. After all the music we went through, we will not say MS Audio is better than MP3 at the high end of the bitrate spectrum (160 kbps included) but is definitely better at the lower bitrates. It is a good compression scheme tragically compromised by a very annoying audible artefact. We can definitely look forward to improvements though. My only worry is that it will be platform limited at least in the sense that the software for producing compressed files will only be available on Windows.

(Rating: B)
 
 

Table of contents
Introduction	TwinVQ (VQF)
Basics of audio compression	Real Audio G2
Methods of comparison	Microsoft Audio 4
Software and hardware	MPEG 1 layer 2 (MP2)
Selection of music for the comparison	MPEG 1 layer 3 (MP3)
Index of results	Conclusion