Re: Call and Response mixing
If you're willing to put down a little cash, Sausage Fattener is an awesome plugin. I feel like I'm cheating when I use it because its so simple and so handy. Obviously there are other ways to get the same effect but its a quick and easy solution.
You might also want to try a bit of distortion on the bus, I've had some luck with that, really short delays can work well too.