Got this frequency line ?

I think that just about everything that's released in the form of movie trailers has compressed audio, and 128k is pretty standard as an MP3 rate.

You may think that audio coded at 128k sounds great, but to me it just sounds distorted - mainly because it is, by the lossy masking process involved in the coding. The people that do audio for films know this, and do their best to compensate for it, but it's never really successful. You have to bear in mind that MP3 has only ever been intended to be a distribution format, and when you use it as a final distribution of material, you have to be pretty careful about various aspects of what you're coding - not least of which is the levels. It's not safe, for instance, to code signals that peak at 0dB, as this often results in clipping where there wasn't any before; peaks at -2dB generally result in a much cleaner file, especially at low rates like 128k. And some sorts of signals really don't do too well in the coding process - anything that's relatively steady (held chords) with something else that changes a lot (singing) over the top is very likely not to sound the same, as the coding process for the steady signals will be compromised by the varying one. The lower the rate, the worse this sounds.

If I send out MP3 progress copies, the lowest rate I'm prepared to use is 192k, and even that's compromised somewhat.