How to fix tinny sound from Dell Inspiron 5000 series laptop speakers in Linux Mint 20 or Ubuntu 20.04 LTS

Linux Mint 20, Xubuntu or Ubuntu 20.04 LTS runs well on the Dell laptop. But, the recent upgrade to Linux Mint 20 or Ubuntu 20.04 LTS caused an issue of tinny sound from the the speakers.

After trying several changes, I tried this below, and at least, using the pulseaudio equalizer, managed to make the tinny sound less. Open a terminal window and enter the following commands.
$ sudo apt-get install pulseaudio-equalizer <enter>

Then run:
$ qpaeq <enter>

If you get error like:
There was an error connecting to pulseaudio, please make sure you have the pulseaudio dbus module loaded, exiting…

and then do the following:
$ sudo vi /etc/pulse/ <enter>
Add the two lines below to the end of the file
load-module module-equalizer-sink
load-module module-dbus-protocol

:wq <enter>

Restart pulseaudio as:
$ pulseaudio --kill && pulseaudio --start <enter>

Then start the pulseaudio equalizer and adjust the sound by:
$ qpaeq <enter>

Adjust the equalizer to your convenience to remove the tinny sound.