really the only output is the MPK midi.  Like I said, I get readings of volume in sonar but no sound
  So I have no idea what MIDI sourceftrack means.  First synth audio output.  synth properties page. Where is all of this stuff?   oh yes thanks I will be audio only from here on out till I can find the responsible parites and blah blah blah.  most absurd waste of time I have seen in six months.  Horrible and I will get help.  Randy 

The Focusrite should already be set as the output, but press P on the computer keyboard to bring up Preferences. Ensure that the Focusrite is listed as the Playback Device and the Recording Device. Find Driver Mode and change it to ASIO. you may have to close and re-open SONAR for the new settings to take effect.
Each audio track and bus will have an input and output, here labelled I and O.
 

 
The TTS-1 soft synth track is output to my Saffire, but I could also choose any of the buses listed.
 
 
You may have to expand the track to see all the parameters. You may have to select All at the bottom. Ignore the colored squares.
 

 
As far as sending the sound to the headphone outputs of your Focusrite, that would be selected in the Focusrite's software, not in SONAR.

So have you gotten sound from anything at all in Sonar?
I gather you have not actually inserted a soft synth into your project? The Insert Softsynth process gives you the options I mentioned.
MIDI itself is just data, information, like sheet music.
You cannot hear sheet music. It must be interpreted and played through an instrument. That's what a soft synth does.
No instrument, no sound. Make sense?

the focusrite is not an option for midi the mpkmini is the only option for input and output.  I'll keep trying to figure this out

i inserted a soft synth made the output of the midi track the soft synth, set  the soft synth to send to the focusrite output.  Nothing, absolutely nothing.  Randy 

Ok. Lets verify that sound is getting from Sonar to your Focusrite.
Click Edit>Preferences.
Under Audio Devices, make sure the Output Driver for the Focusrite is checked.
Under Driver Settings, make sure the Focusrite is selected in both the Playback Timing Master and Record Timing Master.
Under Playback and Recording, what Driver Mode is selected?
ASIO is probably the best option here.

So far so good?
 Play an audio track. Do you have sound?

We'll get to the MIDI/soft synth, but first things first.

ps. I see you have been a member since 2009. Were you using a previous version of Sonar?
If so, were you able to get it to work? I'm guessing yes, at least to a degree. What is different now? New interface? New computer? New version of Sonar?
I'm just trying to get a feel for where you are with the software.

Getting sound from a soft synth should be fairly straightforward IF Sonar is set up properly and you are getting sound in general.
That is why I am asking you to do this stuff.
Please help us help you.

The big boys big boys in Boston responded when I called.  YOu guys are awesome!!! 
Thank you for contacting Cakewalk Technical Support. You will see a recap of our phone conversation below. If you have another support question please visit http://www.cakewalk.com/support/contact/ts.aspx or call 617-423-9021.
Thank you for choosing Cakewalk!

Problem/Questions: MPK Mini MIDI Controller is not communicating with user's computer. Deleted the TTSSEQ.ini file to reset the MIDI Configuration.

Solutions: You can reset the TTSSEQ.ini file by following these directions:
Open the Run prompt by holding the Windows key and pressing [R].

Type "%appdata%" (without quotes) and click [OK].

In the folder that opens, navigate to Cakewalk\SONAR X1 Producer.

Delete TTSSEQ.ini.

So you're up and running, yes?

apologize for the delay.  been sick all week, my elderly parents have been here for medical stuff and work- ah yes work!
anyway, I have got this to work two different nights.  it isn't real easy though.  have to run this erase and recompute program every time and still doesn't seem to connect real easy.  The cakewalk system doesn't seem to pick it up very fast.  Like it doesn't like a certain usb port or I have to switch it.  Anyway. just my third time and it is working now (switched usb ports).  the people on this forum are incredible.  I started with cakewalk 9, then sonar 7 now this x1.  Really incredible. haven't spent a lot of time with this recording stuff.  however I have some really cool and catchy commercials for our business that  I will post soon  Thanks and thanks.