You should be able to make your fans run at a slower speed or even turn off all together when they are under a certain temperature automatically. If you already have the line curve down as low as you are comfortable with, then you might need to have better cooling for you components, so that they run cooler and won't need the case fans as much. Something like a good AIO if you don't already have one. Rubber grommets instead of fan screws can help.
Hopefully this guide can help you set them up.
Submit photos and a description of your PC to our build showcase
See other custom PC builds and get some ideas for what can be done
Services starting at $149.99