how to me mix duet right?

I mean panning one instrument in this case acoustic guitar to e.g. left and second acoustic voice to right
doesn't seem to be right. It sound kinda separated. Should I stretch guitar to stereo? if yes how can I do this ?
thanks

I have already recorded 2 tracks, one with guitar and second with vox.
BTW this guitar track was imported from external recorder  as stereo to 1 track.
Is there a way to split it? I see two waves lines in this track.

bitflipper


The two waveforms indicate that it is already a stereo track. Insert an instance of the Channel Tools plugin to pan each side as needed. If it's just guitar and vocal and nothing else, you'll probably want them both more or less up the middle, either straight-up mono or panned very slightly apart. You can use reverb to give them more of a sense of width, but solo guitar + vox pretty much has to be mono to sound right.

that Channel Tools plugin is I guess not available in my Sonar X1 LE (waiting still for delivery of Sonar X1 studio)
because I don't see it. Is it the only way to spread this tracks? 
thanks

Although the guitar was recorded in stereo, unless a stereo microphone was used it's likely that was a mistake (a non-stereo microphone is inherently monophonic; think of it as a listener with just one ear).

If that's the case, then there is no perception of "stereo-ness" that can be enhanced. In order to perceive any sound as being stereophonic, the left and right channels must differ from one another in some way. So in order to give your monophonic source (guitar) a sense of width, you'll have to fake a left/right difference.

One way to do that is to clone the guitar track and then modify the two tracks such that they are no longer identical.

EQ is a good place to start. A graphic equalizer such as the Cakewalk fx:eq works well for this because you can visually set up two equalizers in a complementary fashion. Just create dips in one that are matched by identical boosts in the other and vice versa. The original frequency spectrum is still represented in full, but different frequencies are emphasized on the left than on the right. The ear can now differentiate between the two and there is now a perception of width.

Another trick is to use different reverb settings on each track. You could, for example, cross-pan two reverbs so that the reverb tail for the left guitar is heard in the right channel and the right guitar's reverb is heard in the left channel. Delays can be used the same way, but for solo acoustic guitar delays must be very subtle or they'll sound unnatural.

You can also change the timing on the left and right tracks. Nudging one of them a few milliseconds behind the other will accentuate stereo perception. This must be done cautiously and doesn't always work. It works fine with distorted guitars in a dense mix, but with a single acoustical guitar it's likely to just sound weird, not better.

Another technique is to use a stereo chorus, either applied to one of the tracks or to both tracks but with different settings. A chorus plugin works by introducing small delays and combining the delayed signal back into the original. This can create an illusion of stereo.

There are more esoteric variations on these techniques, such as Mid/Side EQ, frequency band delays and reverb pan modulation, but they require plugins that are not included with your version SONAR.

Of course, the ultimate technique for wide acoustic guitars is to play and record the same part twice, using different mic positions, and pan the two takes apart. Natural variations in the performance will assure that the left and right versions are different enough to achieve stereo width. This isn't always possible or practical, but if you want wide stereo-ness, it's the best way.