another question - do I still 'normalise' all my audio by 100 %?

mariettemo
another question - do I still 'normalise' all my audio by 100 %?

Not necessary. If the resulting recording is "peaking" between -12db to -6db on the Sonar track (without any effects added) that's a good signal.
 
One thing you should check out as well is the "Multi Inputs" on the front of the Focusrite. There should be a setting to change the input from "Line" level to "Instr" level. The "Instr" setting (stands for Instrument) is for guitars/basses and in some case keyboards that have a low output level.
 
On my 18i6 I have to change the setting within the ScarlettMix software. I am not sure how it would be done on the 6i6 (I don't know if it comes with ScarlettMix).
 
So if you increase the output volume on your keyboard (3/4 to 7/8ths output volume on the keyboard is probably good) and you are still having to crank the input volume on the interface past half way (I generally keep that front trim knob between 1/4 to 1/2 for most things) then you may want to try the Instr setting (if it's an option).
 
BEFORE SWITCHING TO "Instr" TURN DOWN BOTH THE KEYBOARD OUTPUT AND THE INTERFACE INPUT TRIM!!!
 
The setting increases the gain/volume significantly so turn things up gradually otherwise you could be in for a nasty, unexpected blast of extra volume.
 
Cheers.

Hi - I do have the scarlett mix software - how do I need to set it? I don't have the setting to change the input from "Line" level to "Instr" level. There are two little lights next to gain 1 and gain 2 button saying inst and pad but I can't seem to alter them. I thought the gain buttons were just for the microphone inputs actually. There's also a large normalise button on the front too.. 

In the Scarlett MixControl Software at the bottom of the screen you will see two areas that are labelled 1 and 2. Inside the two areas it will say "Input" with two little "LED" light bulb looking things labelled "Line" and "Inst". Clicking those LED thingies will switch/choose the input setting for the multi-ins on the front of the unit.
 
So if you have the keyboard plugged into Multi Input 1 then click on "Instr" or "Line" to choose the setting for that input (and of course if you are hooked up to Multi-In two you would do that in the area labelled 2).
 
The physical button on the front of the interface (it likely says 48v) is for "48 volt Phanton Power" and is ONLY to be turned on if you are plugging in a "phantom powered" mic. That usually would be a "condenser" microphone (there are some other kinds that require phantom power but they are uncommon).
 
Do NOT turn that button on unless you KNOW you have a "48v phantom powered" mic attached. Otherwise it can damage some mics/equipment.
 
NOTE: I am basing my statements about where these buttons and options are on my 18i6 which is a more elaborate unit so be sure to read the Focusrite manual for your interface to double check the things I'm referring to. Just knowing some of the terms and ideas I described should help you figure out the unit a little more and be able to choose the right options for specific jobs/gear.
 
 
Cheers!

BTW the term "Pad" usually refers to ANOTHER type of input gain adjustment. I don't have that option on my interface but I think it generally means a boost of 10db (or maybe the opposite or a totally different level... lol... I'd have to look it up).
 
So it sounds like you might have multiple input options. As in "Line", "Pad" and "Inst". I'm pretty sure "Pad" is another option commonly used with analog keyboard outputs and may suit your needs better than Line or Inst.
 
Check your interface manual and experiement (without blowing out your ears or gear... always turn things WAY down then slowly turn them up when playing with this stuff).
 
Cheers.

A pad will decrease the input level by a specified amount, generally 10 or 20db.

Not sure if you figured it out yet, but being the proud owner of a 6i6 and having plugged just about everything into it might be I can help. 
 
The roland probably plays a demo tune.. use this to set your level
 
First , with digital keyboards setting the level at around 3/4 is sort of close to what we call unity gain. 
The output should be a good match for your rear panel 3/4 inputs. This is the first place I'd plug in as then you can leave it set up and use your front jacks for mikes and guitar. 
Open mix control and play the piano. The level meters for 3/4 should be showing a good level. 
If not try choosing the Hi Gain or the Low gain down at the bottom and see which gives you close to unity level. 
 
If this doesn't work then try the front combi jacks.
Try the mix control input 1 on line first, if low then try inst,, 
You'll see the levels for 1/2 and hopefully they are OK. 
 1/2 input Line is for mikes and is a lower level
 1/2 input inst is for guitars and the level will jump up. 
 3/4 input Hi Gain gives you a hotter signal than Lo Gain. 
 The pad is only needed when a signal is abnormally hot. 
 
Note ,, the level controls in mix control do not change the level going into Sonar. They are for setting your monitor mix. 
You can only set the level going into Sonar with the input 1/2 Gain controls on the front panel.
3/4 inputs can only be adjusted by changing the Hi Gain, Lo Gain or using the output control of the instrument or pre amp your using. 
 
 

I'll add that you might be better off in the long run finding a VST piano that outshines the Roland. Not hard to do. 
I see it only has midi connectivity ,not USB but that's fine as the 6i6 has midi ports. 
If you upgrade your Sonar to a version with True Pianos you can then use MIDI to record and playback via the VST. 
LE doesn't have very good sounding VST's, so don't judge Sonar by that. 
But it's pretty good for recording and fully capable midi editing. 
 
If you get the analog levels set up properly you should not have to normalize. 
Sonars normalize is pretty simple compared to that found in a wave editor, most would have a default of -05db and a few others. So go with 98% at least. never 100%. 
 

Hi Everyone
 
Sooo...it turns out my Roland FP50 has an unbalanced output which is why the levels are so low. I tested another keyboard and everything was fine - so it's definitely the keyboard:-( I tried recording switching levels from low gain to high gain in my focusrite mixer which improved things, except there is now a ringing sound! I then opted to insert the jacks into the front of the interface and switch from line to instrument on my mixer, and the levels were great in my focusrite mixer. However, I couldn't see the levels in sonar, and when I played the audio back there's no sound! why is that? Also, in order to record my keyboard in stereo and vocals at the same time, I'm going to have to upgrade to an 18i6 I think ??

Most all keyboards have always had unbalanced line level stereo outputs. This is not the reason it is quiet. It most certainly should be anything but.  The output is the same level as that of a CD player for example.   I'm baffled at why you can't get that to work with the rear panel 3/4 inputs set on HI GAIN. Are you sure there's not an issue with the Piano itself. All of what your saying points to something fishy with the piano.  Have you tried plugging it in to an amp? My Roland controller can have it's velocity tampered with which will certainly make it output lower levels. How loud are the headphones? Try a set of good headphones pugged into the piano's headphone jack.  
 
 And you certainly won't need a new interface. it will work with the rear jacks  once you sort out why it's output level is down.
One other strong possibility is your cables.
Have you tried different cables. Regular 1/4" TS guitar cables are what you would be using.