Is direct monitoring possible with Tascam US-16X08?

I picked this up (used) as a backup recording interface.  Everything checks out except I can't figure out how to direct monitor (if its possible).  Only thing I found to do is enable echo on each track in Sonar.
 
 
 

I see I can change Line out 1 and 2 to Master L and R, instead of computer.  That allows direct monitoring but the levels are goofy if trying to track with existing tracks.  The output from Sonar has to be dropped way down to be able to hear the input at the same time.  e.g. I plugged an SR16 drum machine into channel 1 (through a D.I. Box) and set the level to -4.  I had to drop the Sonar output level way down so I could hear the "direct" drum channel. 
 
Either I'm doing it wrong or it just works different than other interfaces (including my main unit an MOTU 896mk3 Hybrid and the Roland Octa-Capture I used have as backup unit).

That is the way I set it. 

I am set up for  recording session tomorrow using the drum machine.  I have an XLR patch panel that is wired to my MOTU unit.  The output on the SR16 is 1/4" and I have a D.I. box to convert it to XLR.  I just moved the XLR cable to one channel on the Tascam unit.

I got it going last evening at least close enough that I could use it if needed.  Direct monitoring for recording is not an issue, now that I have the Line Out 1 and 2 set to Master L and R.  I worked with the levels in Sonar for tracking and have it that I can work with it, if I need to track with a recorded project.  This will be used as my backup recording interface so after getting it configured, it may just sit in my rack and never get used.
 
Thanks/Jack
 

Having picked Tascam over Focusrite, I've had no previous experience with Mix Control. I just spent a few minutes going through their tutorial for Mix Control, the Whiskey Tango Foxtrot edition, and am at a loss for words.
 

Ran into this the other day with a TASCAM US 20x20.  I almost shot myself trying to get a single mix out of the headphones for the players.  Switching between pages to set levels and then outputs is a b ... bear.  Esp. when several players looking at you, waiting.  Their look was more pitiful than my dog before breakfast.  Glad you got that sussed out early, firebird.
 
I don't use the 20x20 enough to remember what I did the last time I used it for a bigger session.  But I think I'm finally starting to understand the relationships between the different pages and how they work as a single unit.  But why companies don't follow the standard "mixer" layout is beyond me.  I'll take familiarity over a small boost in flexibility any day, esp. under deadlines. 
 
However, I managed to get a direct mix going to the proper outs.  The soft mixer works from the hardware inputs, while the output settings let you choose between the mixer and direct computer outs, as far as I can tell.

We once contracted to do a local festival, Collectively all us local bands had the makings of a monster PA system,, but we had didily squat for monitors, so we had the organizers rent a "real" monitor system.
Hmm, we all said as we opened the 3'x5.5' road case for the mixer... what the heck is that? 
Oh that's a monitor mixer! Or better known as a Matrix mixer. WTF, look at all those knobs!!
Anyhow it was very logical once you starred at it long enough and saw the beauty of the system. We even managed to patch in the rack full of outboard gear they sent along and make it all work. 
And got lots compliments on how great the monitors mix was coming through.
Not bad for a bunch of weekend warriors who had never seen anything bigger than a 24 Channel 4 buss.
 
So that said,, why can't these interface people stick to the standard formats used world wide.
I can understand people who have never worked with big consoles being confused, but making it so even those of us who have run almost every type mixer on the planet cannot figure it out?  Not only that, the software seems a little buggy too.