No root needed, Sony Xperia Z C6602, C6603 record calls perfectly in two sides.
Please use these settings to record calls:
- Record Mode: test 4, 2, 3 and 1
- Record Format: WAV
- Tune Audio Effect: No
- Tune Audio Route: Group3
Works well for all Android 4.2.2, 4.3, 4.4.2, 4.4.4, 5.0.2 and 5.1.1.