Yes they will however that quality is now about equal to youtube sound and the average person thinks that is fine. Personally I think it sounds terrible but with all the guns and people yelling you can not notice the difference. Also it is not as though these were really high quality audio files to start with.

Also there is no way to disable ambient music on a client by client basis without crashing the server. One way you could do it though it to replace the music files with blank txt docs that are renamed to the music file. This way when your computer tries to play the music it will get an error and play nothing. In addition you will not dl the files b/c you already have files with the same name in the directory and the downloader can not overwrite files.