Also, it should be noted OP is talking about a piano track which is one of the scenarios where a stereo track recorded from a stereo pair of mics is actually desirable. Kind of like drum overheads/room mics. It's actually more of a pain trying to manage two mono tracks in these scenarios (you don't want two sets of effects and generally want them to mirror each other, etc...).
 
Splitting that stereo piano track could cause more pain than it's worth whereas if some finicky stereo shenanigans are needed CT can do it without splitting the track.
 
That said... it would be nice if Sonar stereo tracks could do the stuff CT does with on track controls.

Hotice226
I recorded a piano track in stereo using my Stereo Channels 3-4 on my Focusrite Scarlett 6i6. Track levels are great and the pan function is fine, but I need a way widen the stereo field (or change spread placement or narrow on future projects) without using effects. Is there a way to do this on a stereo channel or do I have to create 2 separate channels (one for left and one for right) and route them to a piano bus to accomplish?

If you send the stereo track to a surround bus you'll have quite a bit of control.  Sorry, I don't remember where I first heard that, but I've used it.
 
HTH

jimkleban
Not sure if Channel tools is better.... i feel like i can control stereo fields better with 2 mono tracks.  Don't get me wrong, channel tools is great if you want to additionally add delay for pseudo automatic double tracking but two mono tracks give me the feeling of more precision in reducing then moving the stereo field.  I probably will be proven wrong here and I hope I am so I can learn something now.
 
Jim

 
Think of Channel Tools as a "Stereo-to-Dual-Mono Converter." That stereo track is actually two mono tracks sitting in the same "container." Channel Tools - I mean, the Stereo-to-Dual-Mono Converter - basically opens up that container and treats the stereo track as two mono tracks. 
 
But it's actually more flexible than the Pro Tools dual panpot approach because not only can you move those two mono tracks anywhere you want in the stereo field, they can have width in the stereo field.
 
If you have "The Big Book of SONAR Tips," go to page 16 for the tip "Add Pro Tools-Stlye Dual Panpots to SONAR." Here's what it's about:
 
From time to time, some people wish that like Pro Tools, SONAR had separate panpots for the left and right channels. The reason why Pro Tools has two panpots is because it traditionally treated stereo as two mono sources, very much like the hardware mixing consoles that were common in the mid- to late-20th century. Like most DAWs, SONAR does understand the difference between stereo and mono signals. This is why for mono tracks the panpot acts like a traditional panpot, but for stereo signals, it acts like a balance control.
 
However there are advantages to the dual panpot approach, as it allows “weighting” the stereo image more to the left, right, or center. The ultimate solution is the Channel Tools plug-in, which not only allows each channel to pan anywhere in the stereo field, but also has a Width control so that each channel can spread across part of the stereo field, or all of it.

While flexible, you might not want to have to open up Channel Tools to do this kind of advanced panning. However, it’s possible to integrate Channel Tools’ functionality right into the Console View’s channel strips by using the Channel Strip’s “Show Assignable Controls” option.
 

Just make a copy of your stereo track and then pan at will left and right.. Dave lazy tip  on the day. ;)
Hum?  does that sound right?
 
 

You changed your name AGAIN, Dave?
 
...
 
I'm out.

Beepster
You changed your name AGAIN, Dave?
 
...
 
I'm out.

lol, yes, long ago... I do that all the time. I just get board and like a change. I have changed band names a few time a year as well... build new logos, websites.... . You think I'm hiding from something? ;) We should really be friends... its been a long time...  rejection is futile... :) peace!

Anderton

jimkleban
Not sure if Channel tools is better.... i feel like i can control stereo fields better with 2 mono tracks.  Don't get me wrong, channel tools is great if you want to additionally add delay for pseudo automatic double tracking but two mono tracks give me the feeling of more precision in reducing then moving the stereo field.  I probably will be proven wrong here and I hope I am so I can learn something now.
 
Jim

 
Think of Channel Tools as a "Stereo-to-Dual-Mono Converter." That stereo track is actually two mono tracks sitting in the same "container." Channel Tools - I mean, the Stereo-to-Dual-Mono Converter - basically opens up that container and treats the stereo track as two mono tracks. 
 
But it's actually more flexible than the Pro Tools dual panpot approach because not only can you move those two mono tracks anywhere you want in the stereo field, they can have width in the stereo field.
 
If you have "The Big Book of SONAR Tips," go to page 16 for the tip "Add Pro Tools-Stlye Dual Panpots to SONAR." Here's what it's about:
 
From time to time, some people wish that like Pro Tools, SONAR had separate panpots for the left and right channels. The reason why Pro Tools has two panpots is because it traditionally treated stereo as two mono sources, very much like the hardware mixing consoles that were common in the mid- to late-20th century. Like most DAWs, SONAR does understand the difference between stereo and mono signals. This is why for mono tracks the panpot acts like a traditional panpot, but for stereo signals, it acts like a balance control.
 
However there are advantages to the dual panpot approach, as it allows “weighting” the stereo image more to the left, right, or center. The ultimate solution is the Channel Tools plug-in, which not only allows each channel to pan anywhere in the stereo field, but also has a Width control so that each channel can spread across part of the stereo field, or all of it.

While flexible, you might not want to have to open up Channel Tools to do this kind of advanced panning. However, it’s possible to integrate Channel Tools’ functionality right into the Console View’s channel strips by using the Channel Strip’s “Show Assignable Controls” option.
 

All the chatter has been super helpful, but this snapshot from "The Big Book of SONAR Tips" is money! I might have to snag my own copy. Thx everyone.

Hotice226
All the chatter has been super helpful, but this snapshot from "The Big Book of SONAR Tips" is money! I might have to snag my own copy. Thx everyone.

I would highly recommend it. Not that I'm biased, of course.
 

to the OP,
Have you ever had a mix where frequency's are fighting against each other and you just need some kind of way to get a track to stand out (Vocal, Guitar lead, exc) yes...well then work on EQ first .
But if you have exhausted all resources, use channel tools. it will take a little bit to get the jest of it, even though it is a fairly simple plug in to use it manipulates the stereo field, tricking your ear in to thinking the track "Pops out" more.