You guys were playing loud music with the doors open, 50 yds from people's homes. Of the many people that you probably irritated, one guy came to talk to you about it. He expressed that it bothered him, but from the OP, did not make any threats. He asked you to consider others, and even shared his personal experience about why it was particularly difficult for him.
I get that it was uncomfortable for you, and certainly reasonable for you to have had your guard up out of concern for what he might do. But he was apparently self-aware enough not to make threats, as many people would have. Keep in mind that you guys created the situation, and from his POV, his choices were to sit there and stew, talk to you, call the cops, or do something irrational. He chose to talk to you, as people.
Have you ever heard the expression, "If you have a problem with me, then why don't you say it to my face?" That's what he did. Nobody got hurt, and when he spoke his peace, he left.
I can't take your side just because you play bass. You were annoying people and he came to talk to you about it. If he had made a threat, then it would be different.
Find another place to practice. Look for a place with sound isolation and climate control. Then move on and be the kick-ass band that you want to be.