One speaker louder

i had the same problem for a while it just takes a lot of patients. it is all about first reflection and speaker placement

I agree with swapping speakers left to right as a troubleshooting technique. This may tell you if the problem is a speaker or something else (placement, electronics, source material).

I swapped them, but there is a real difference. You can still tell they are the same speaker, but one is quieter and less open.

If the quiet and less open speaker follows the swap, then the problem is the speaker, and not placement, equipment or source material.

If the swap results in the same channel sounding quiet and less open, then the issue is with something other than the speakers.

IMO.

I swapped them, but there is a real difference. You can still tell they are the same speaker, but one is quieter and less open.

Bad news. Next step (if new or recently purchased) is to take grills off and check no packing material is in the way - also check to see if a driver is completely dead and then contact the seller. Otherwise - you might be able to open them up and check connections and contacts and the crossover. What model are these?

Any chance you overdrived them - even briefly by mistake?

Finally you are looking at a repair or replacement driver...