Phone Holder (customizable)
thingiverse
The space at the bottom allows the speaker's sound to direct into the driver's direction. Currently, the size fits perfectly for a Galaxy S9 smartphone with this transparent case available online. It is small enough that the smartphone won't jump out even if it gets very shaky. This might depend on the printer used, however. Use cable ties to securely fixate the holder in place.
Download Model from thingiverse
With this file you will be able to print Phone Holder (customizable) with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Phone Holder (customizable).