Is the speaker volume of your phone is very low ?
You can increase the speaker volume yourself, it is very simple.
Here are steps:
1. Install Mobileuncle MTK Tool
2. Open Mobileuncle MTK Tool and select Engineer Mode
3. Select Engineer Mode MTK
4. Swap to Harware Testing
5. Select Audio
6. Select Loudspeaker Mode
7. Here you will find Max Volume Value 128, Change this to 145 and press set.
8. You can set this value up to 160 but above 150 is not recommended else it may damage your speaker.
9. Now you can close Mobileuncle MTK Tool.
Now you can check the volume of your speaker and feel the difference.
I have tested this method on my Lava Iris 501.
Works with MTK Chipset only