You can alter things a little if the vocals are buried slightly by using stereo to M/S conversion. Push the mids up a little on the M signal then convert back to stereo. You will end up with a centre image that has a little more presence hence it may cut through better.
(As long as there is not too much other stuff around near the centre that will clash with the vocal range) You can also use this approach to pull centre images down a little if they are poking through too much as well.
Nothing beats getting it right in the mix.
Dynamic EQ requires you to think about the threshold that has been used with the EQ. And that applies to either tracks, buses or a final mix.
Then you need to think about what happens to the EQ (
boost or
cut) when the signal is
below and
above the threshold. A lot to think about.
With multiband compression the main thing is the bands will usually always reduce in gain once a threshold is reached. It is important to get bands all reducing gain by very similar amounts so the overall EQ stays intact. It can seriously be put out of whack if a multiband compressor is set badly. ie one band reducing way more than the others.
With dynamic EQ the EQ changes can occur in a band too but they can boost as well as cut. Not to mention that the dynamic EQ effect can happen either under or over the threshold so it is more complex in a way.
I find the better you are tracking and mixing the less you should need this. It is more about repairing than creating. Although it could be used to advantage in a mix. I prefer to automate EQ and volume changes instead. You have more precise control over that.