Technical Dilemma

I recently purchased two Paradigm LCR-450 speakers on eBay: each one from a different seller. One works fine, the other is defective in that the sound emanating is weak and muffled. My first thought was a faulty crossover on the defective speaker, so I switched crossovers, and lo and behold the problem did not follow the crossover. The crossovers are not identical as well. One has an additional capacitor and the electrical values are not the same on some devices. Before I pursue the possibility of a return on an item that "cannot be returned", I am seeking advice here.