That is a good approach. Nothing like playing with others to make you see yourself in new ways.Get a guitar and an amp. Learn to play a song on it.
Then make them play along to your guitar playing. When they realize they can't hear themselves, most likely instinct will tell them to hit with a bit more force.
Yep, great answer. Learning how to play in a loud band is the best way to measure your limits. I thought I could hit pretty hard until this new rock band came together for me, last year.That is a good approach. Nothing like playing with others to make you see yourself in new ways.
I have been playing since 1983 and I have never, ever heard anyone complaining about a drummer playing too softly, but I have often heard the opposite. So the OP shouldn't view soft playing as a bad thing necessarily.