I am using Platinum with Scarlett 2i2. When I record vocals, I don't hear my own voice in the headphones. So I turn on the input echo on the vocal track. I can now hear but there is a significant lag which is distracting enough while recording so I have to turn off the input echo. The latency is showing 10m/sec with buffer size 2 in the driver preferences.
The scarlett has got direct input monitoring but I can hear my voice clearly on the headphone only if I turn the mic gain knob  to the max on the device. This obviously causes the recorded signal to go too high in Sonar.
Any hints on how I can resolve this ? Is the driver or interface or the cable (which is 5 meters long).

Try to put Volume to max on the MixControl for the line of your Mic, and with de MixControl Too turn down the Volume of the output of the DAW & Not turn on the input echo in the DAW.
 
 

you have the Mix control software installed ?
you have the Scarlett selected in your devices and running in ASIO driver mode ?
 
try using a lower buffer size like 4.0
 
I have an 18I8 and I use input echo all the time.
I go in to my Mix control software and set it up for "Daw tracking".
this works perfect.

Mix Control software is only for premium Scarlett devices.
What driver version are you running?

I downloaded and installed the latest driver and the mix control software. Mix control does not seem to detect the hardware !
 

Mixcontrol software is only made for these devices: Scarlett 8i6, Scarlett 6i6, Scarlett 18i6, Scarlett 18i8, Scarlett 18i20

You might want to confirm what driver you are using. I would recommend the 2.5.2 driver.
 

RSMCGUITAR
You might want to confirm what driver you are using. I would recommend the 2.5.2 driver.
 

I didn't notice the number but I downloaded the latest one from their website today.

Sorry, which generation Scarlett are you using? (1st or 2nd)

First, Is the music playback ( computer)  loud in the headphone when the headphone control is at say 1 o'clock?
What signal are you getting from the mike? ,, does it go into the red if you shout out?
 
If the music playback is loud and the mike is not, then there's something wrong with your mike set up, cable or the setting your using..also is this a phantom powered mike? USB power is a known factor with pour performance with phantom powered mikes.. You need an interface with a power supply. 
The 2i2 is certainly a pour design for interfaces from all the weirdness reported here due to it's lack of certain features.