If you are uploading to YouTube use the YouTube preset that comes with the AME that matches your project settings. Only monkey with the presets if you have carefully studied formats, compression, YouTube standards and recommendations, and you have become an expert. Any messing around with the switches without a really good understanding of what they do is just asking for trouble because YouTube, and any other streaming service, will look at your upload and re-compress it to fit their standards. The farther off you are from the recommendations the less likely that the automatic re encoding of your video will be high quality.
On another note, preparing Audio for it's best reproduction also requires a fairly extensive knowledge of hot do mix and prepare audio for delivery. AE is not to tool to use to make audio refinements. Study up on Audition and make sure you have a good understanding of how mixing, eq, compression, loudness and everything else effects the final quality of your audio. Again, there is no single click this button and set this value answer to your question. It requires time, study, expertise and skill. That's why a good audio engineer is $$$$ per hour, and worth every penny.
One more thing. If you really want to to a great job you can't accurately judge audio without an equalized audio playback system in a balanced room with good speakers set at the appropriate listening distance. There's no way to know exactly what you are getting without the right tools.
I hope this helps. If you are not happy with the audio you are getting when you upload to YouTube and you are using the presets in the AME then your audio problem is not in the compression settings, it's in the audio track.
Hi thanks for your reply. I'm not using AE to refine audio. All audio has been professionaly produced using Pro tools, mixed and mastered by engineers. My question was about rendering settings and nothing to do with mixing? I have produced the music videos and was simply wondering if the youtube preset was infact the best quality option to use. I'm not familiar with AE as I normally use FCP. I will use the youtube preset then. Thanks