So I noticed that my Sony MDR-1RBT is not working on aptX codec, did some searches and here are the steps to get aptX codec capability.
1. Download the io tool:
2. Bluetooth Explorer -> Tool -> Audio Options: Force use of aptX
3. Reconnect your bluetooth headphone
To enable aptX on the headphone, press volume + and power for two seconds when powering on. The blue indicator will blink 3 times when on aptX mode.