Encoders express testing (part 2):
MS Windows Media Audio (.WMA), Ogg Vorbis (.OGG) and Liquid Audio (.LQT)

Resulting amplitude-frequency response in the bigger scale:

Resulting amplitude-frequency response:

Resulting amplitude-frequency response in the bigger scale

Brief conclusions 

WMA has simply surprised on 64 Kbps: while all coders have cut off a signal on 10 Khz (giving 22-kilohertz output files), WMA has fairly fulfilled all frequencies up to 20 Khz, and done this besides qualitative enough for such low bitrate. But it is necessary to assume, that such achievement on all frequencies, probably, has an appreciable effect on the signal quality in the lower strip of frequencies, but also here impossible to say anything bad: during listening WMA sounded appreciably better than opponents. Thus, preview of songs, which are usually done using MP3 64 Kbps, would sound much better if they was coded using WMA. MP3 and LQT (AAC) are not remarkable - the give out files WAV on 22 Khz, which means, with frequencies limited by 10 Khz.

On 96 Kbps LQT (AAC) behaves obviously better than MP3: the strip of saved frequencies has extended up to 15 Khz, that, certainly, has a very appreciable effect on sound. However, nevertheless, WMA all the same is in the lead in quality. As to LQT Dolby AC-3, by the diagram he behaves slightly better, than LQT AAC. But as to subjective recognition - it is difficult to determine the leader between LQT AAC and LQT AC-3. 

In the test on 128 Kbps instead of MP3 participated OGG (because its minimum average bitrate is 128 Kbps). LQT AAC in this test has cut off all above 18 Khz, though its sounding is absolutely good. But here has lagged behind yet WMA - OGG obviously fulfils all strip of frequencies even not interrupting on 20 Khz . The sounding of LQT, WMA and OGG in this test begins difficult to compare, and it is necessary to believe the diagrams. But, nevertheless, it seemed, that WMA and OGG sound better than LQT, though it can be simply my preconceived opinion. As to LQT AC-3, he is simply ñ00l: its diagram well repeats amplitude-frequency response of an original signal. Its sounding is obviously very good too. In this test, by the way, participated LQT AAC Streaming and LQT AAC Transparent, any unexpectedness had not taken place - they behave equally.

On 192 Kbps there was happened precisely what I supposed right in the beginning: the diagram of WMA has lagged behind on accuracy from LQT and OGG. And there is one explanation. WMA even on 64 Kbps fulfilled almost all spectrum and it indirectly means that WMA uses an "artful" psychoacoustic model. And, now it proves to be true evidently on the diagram. LQT, though did not fulfil so qualitatively all the spectrum on the top, he nevertheless, probably, repeated an original signal more precisely in fulfilled range. WMA at the expense of some shifts with a spectrum showed in the whole best reaction to all frequencies, but, thus, the signal by it was deformed. OGG shows on 192 Kbps quite good results and, probably, it appears a little bit better, than WMA. LQT AC-3 - is very good, it's diagram precisely repeats the diagram of the original signal. Who is the best - OGG or LQT AC-3 - is difficultly to say.

In the whole. MP3, unfortunately, is noncompetitive. LQT AAC on the low bitrates saves the limited spectrum of frequencies, but thus, probably, deforms the signal a little. On high bitrates LQT AAC shows quite good results. WMA at the expense of use obviously artful psychoacoustic model shows on the low bitrates much more good results, than the opponents, on the high bitrates results remain quite good, but the distortions of a signal on the diagram can be noticed easily. It is very difficultly to say how (bad or good) it influences on perception of sounding. As a whole WMA shows one of the best results. OGG participated not in all tests owing to impossibility of coding on 64 and 96 Kbps. In the tests on 128 and 192 Kbps OGG has shown the best results. Who is the best - OGG or WMA is very complex decision, but the diagram of OGG nevertheless is exacter. As to LQT Dolby AC-3, it is very qualitative codec. And, if on low bitrates he does not show the best results, on 128 and, especially, 192 Kbps is a very qualitative decision.