If a vocal needs THAT much eq work, I maintain it was recorded like crap in the first place. Outside of an effect purpose, and even then I question it, I would sooner re-record an obviously badly recorded vocal. The ONLY time I'd go through that much trouble is if I were IN trouble and couldn't do a retake. I have used a modified version of this a couple of times for an exciter effect, whereby you eq out everything but extreme high freq's on one and then blend it with the original and it worked well. But that's an occasional thing and there's plugins that can do that just as effectively these days. For your example, you can also use a multiband compressor and get the same result- using it as an eq shaper. You can also use a four or six band parametric eq and notch or boost whatever you need. It's not that the technique you mention is a bad one. As always, anything can be the perfect thing to do at the time. But generally speaking, that kind of technique is rather heavy handed for eq'ing a vocal. I'd reserve it for an extreme fix for a badly recorded vocal, not a go-to way to eq a vocal all the time.

If there's one rule that good to live by it's record well going in. Outside of effects maybe, you should not be spending all your time and resources try to fix things that were badly recorded in the first place. If you need five plugins to get the sound right or extreme measures, something was done poorly during recording. Simple is almost always better than complicated.

Dan

My YT Channel- http://www.youtube.com/user/dfizzbom