1/4" vs XLR out of BDI21?

[wemmick]

I'm a fairly new player and my "rig" is built around existing PA equipment we already owned for theater classes my wife teaches to kids. The main speaker is a Behringer Eurolive B212D powered speaker and I added a Behringer V-Tone Bass BDI21 modeler/driver/DI between my bass and the speaker.

The BDI21 has both 1/4" and XLR outputs and the B212D has both 1/4" and XLR inputs. I'd like to understand better the difference between the two -- aside from the shapes of the connectors, of course.

I've played a bit with each -- connecting to the same connector on the speaker (XLR to XLR or 1/4" to 1/4"). The 1/4" is much louder, but otherwise they seem to operate similarly.

Is there an advantage to using one vs the other when connected to this speaker?

Is there an advantage to using one vs the other when connected to a mixer?

What risk is there in damaging any equipment by using the wrong output?

[Pollinator95]

If you´re playing a gig and you have to take your bass directly to the soundman via a cable, use the XLR. The 1/4" loses clarity when using a long cable.
And I don´t know about the loudness thing. Are you sure the XLR out is affected by the master volume on the pedal? It´s probably a fixed output, and your master is just set lower.