Well, I am kinda wondering, what levels you guys recommend for guitars, bass, and vocals. Also, when mixing, where do I need my levels to be at. I just thought of this for some reason. I get my double tracked guitar bus to -12, my single bass track to -12, and vocals about there as well, should I be bringing them up once I am done applying eq and effects?
First, there's no possible level recommendation for individual instruments. That is a balance issue that should be done by ear and it's all subjective to the material. How long is a piece of string?
Second, nowadays good level practice is to never go anywhere near 0dBfs but to still operate withing the optimal range of your gear [and software]. This includes your preamps (unless you are going for a sat/distortion effect), your converters, and your plugins. The optimal range is difficult to define because all gear is different and exhibits different distortion characteristics at different levels.
Furthermore, not all plugin processing is created equal and some plugins perform better at lower levels. It all has to do with their internal mathematics going on and how the plugin handles temporary overs that might occur. This can happen despite the fact that the output is not clipping. Either way, it's best to keep your levels low so as to eliminate the possibility of this happening.
It also comes down to the analog components in your converters. Manufacturers often skimp on these components to save money in R&D and even though you might not be clipping, you might still be picking up distortion at your DAC because of either 1. inferior analog components, or 2. intersample peaks.
All that being said, it's good practice, in my view, to keep your levels below -12dBfs and try to keep your master bus RMS reading at around -18dBfs.
Lastly, always audition processing at the same perceived level as the original. How else will you know if you've improved the situation?
Cheers
