A:Answer Hi Dt,
Here are the instructions on how are you going to adjust the bass/audio of your Pioneer - 7" - Apple CarPlay, Android Auto, Built-in Bluetooth - Multimedia Digital Media Receiver - Black:
Select or customize the equalizer curve.
Select a curve that you want to use as the basis of customizing then touch the frequency that you want to adjust.
I also attached here the link where you can access the full information of the manual:
https://files.bbystatic.com/W6PGGSLDN%2BLj4OrO6D3FCQ%3D%3D/Use%2Band%2BCare%2BManual
Pioneer Products
Lisa
https://www.pioneerelectronics.com/PUSA/