First of all, your jam space should have some kind of soundproofing, and you don't play at concert volume in a residential neighborhood. That being said...
I'm assuming you're in a private home and not an attached apartment, yes? If so, and if everything you said is true, then let him call the cops. There's one in every neighborhood, that guy that thinks because he pays taxes he's got a right to complete silence. He doesn't. You have rights too; as a property owner, of reasonable enjoyment of your property. That means you can play music at a reasonable hour and at a reasonable volume, which is what you say you were doing. Carry on, just don't be an obnoxious ass and you should be fine. If the cops have any common sense, they'll come out and listen for themselves. I have had the cops called twice in a decade for loud rehearsals at my home. Both times, cops said they could barely hear it at the property line so we were ok as long as we didn't get any louder. Both times they asked how late we planned on going. We're always finished by 7:30, maybe 8:00 pm at the latest. One time we got a gig out of it; cop liked what he heard and hired us for a police function. To this day, one of the most fun gigs I ever had; nobody parties like a bunch of cops... for real!