Speaker sound is too low on max volume

I moved recently, and left my old speakers behind (I was going to get them hauled off, but I may get them moved over with the last batch of stuff). I purchased a set of Mackie Studio CR3 speakers a year ago and finally unboxed them to use, hooking them up after the move. They’re plugged in through line out into my Gigabyte X470 Aorus Gaming 7 motherboard, right where the old speakers went. I am running Windows 10.

It’s the green port and everything.

With volume turned up to max, it sounds like I am listening to a conversation on the other side of a room (not a big room). If the AC is running it can sometimes be hard to hear what is coming out of the speakers. Volume on the speakers is turned up to max because if I go any lower I very quickly can’t hear anything at all. The volume in windows is also set to max. Levels are set to max. I’ve pushed every slider I can find to max, just to be sure. This doesn’t help, except if something isn’t max I can’t hear anything basically. I’ve tried blowing out the port with compressed air, which didn’t help. Before I moved, on the old speakers, everything worked fine.

I picked up a cheap pair of Creative Labs Pebble 2.0 speakers and tried them, but I have the same problem – sound is far too low with everything cranked up.

It’s possible the move caused some sort of physical issue. I may bring back the original speakers just to try again. But the fact that two different sets of speakers have the problem makes me think it’s either the port or something in Windows I am missing. I am unclear how to further diagnose the issue.