I have same problem. I bought Razer Kraken X lite today and cant find activation code for 7.1 anywhere….

Do we have to buy an activation code from thx software? so we can enjoy the 7.1 features ?

Does this work for you ? If you find a serial number on your device. 

7.1 Surround Sound Support & FAQs (razer.com)

• How to get an activation code (Razer ID account required)

Non-registered Systems

Please enter your device serial number.

How to find the serial number.

Registration / Technical Support - Razer ManO'War 7.1 Master Manual nPage 5] | ManualsLib

I've tried it, but the serial of my product is not listed ,,
Maybe my product doesn't include activation code for razer synapse 3
For a while i am using 7.1 features from razer synapse 2