As you probably know (or suspect) there are 2 horns.
The other one is hard to see, it's under the right headlight.
Try disconnecting the "easy" one (in front of the radiator) and see if the remaining horn (under the headlight) sounds wimpy or tinny sounding. We've replaced a fair number of horns. The one under the headlight is better accessed from below, after removing the front apron.