No energy in the vocal tracks comparatively (at least that's how I justify it in my mind).
You have a raw Mic track .. usually these need help compared to pre-recorded or RTs.
Unless you push it through the signal chain in the first place.
Mac wrote a good article on gain staging years ago that helps with getting the best signal ..
http://audiominds.com/gain.html /Thanks to Don for keeping this info alive for so long
//thanks to Mac for writing a lot of it in the first place
/// You must be audio minds!
//// (4 slashies!) This is old school basic info but still applies; learned a lot on this site and forum back in the day