Remix of PiGRRL Zero Bottom Case Beefier Joint by SNEAKxxATTACK with space for 20mm speaker and 3.5mm switching audio jack.

I was able to fit a Adafruit 2500mah lipo in this case instead of the 2000mah.

The 20mm Speaker is pressure fit. The 3.5mm jack might need some hot glue or superglue.
You will need a mono amp and RC Low-Pass filter shown in this guide:

https://learn.adafruit.com/introducing-the-raspberry-pi-zero/audio-outputs

UPDATE: 12/7/2020
Larger holes for speaker grill for cleaner sound and reinforced case, The clip at the back has been slimmed down to avoid hitting the pi when closed.

Creality

Ender 3

No

No

0.12

30%

I tried printing this with ABS on a BuildTak like surface at 80c with glue and got extreme warping so I would not recommend printing this in anything but PLA.

As for PLA, I printed on a BuildTak like surface at 50c without glue and got good adhesion with no warping but some elephants foot which has since been resolved. Furthermore I do have a BLTouch which helps alot with bed adhesion.

There was some stringing that was easily removed, and some blobs/ print imperfections that were cut down with a side cutter.

I used Autodesk Fusion360 to modify the file. This was actually my first time using fusion 360 as I had just switched from 123D Design.