Given that Roland manuals are not know for providing idiot-proof manuals, I want to see if I have this straight, please:
 
1-I need to solve latency issues for a singer. (For some reason, it doesn't bother me, but I definitely hear it, even at low ASIO buffer settings.)
2-It *appears* that if I open the VS-700 utility in Sonar I will be able to use Direct Mix; but I *think* this is only for input signals.  Previously recorded material will still be mixed on the console.
3-If this is true, then will Sonar magically disable the main console mixer for the input(s) while I am using Direct Mix?
4-I can't find an on/off switch for the Direct Mix console.  I assume it is activated when I pick one of the outputs (e.g., Main).
5-This means latency recording virtual instruments will not not improve, but external synth latency will.
 
Do I have any of this right?
 
Thanks!

I have sold my VS-700 for a few months. So I don't know.
For recording I use always an analog mixer, so the latency is always 0.
I give the input (micro) simultaneously to the audiocard and an analog mixer + playback. Thus the singer himself can regulate how loud he hears himself.
 

Thanks, Thomas.  I was hoping Craig would respond since he is an expert on the VS-700, but he is a very busy guy.
 
Take care.
 
PS I don't think the latency is too bad with a low ASIO buffer setting, but anything that distracts a singer need to be resolved.

For the VS-700 (or any other interface) your direct mix is always going to be zero latency since you're outputting the signal before it runs through the playback buffer. Using that, you'll always be able to monitor your dry audio input signals on top of playback.

2-yes
3-no i.e. you need to ensure that yoy have Sonar input echo off for the tracks you want to use direct mix on vs700
4-yes there is no on/off ... just route it to the direct mix output
5-yes

FWIW there is no latency on direct mix channels. In case you use a large buffer your sonar mix will have this buffer to compute your mix and hence it will be late. Yet you don't notice as this mix is what you record against it. Once recorded sonar automatically moves your recording forward to compensate for the delayed playback you recorded against...