Lower volume with some XLR's?

I just re-terminated a pair of interconnects from RCA to XLR for use in my Home Theater System. I currently have one pair of these same cables in the system with factory XLR termination. The pair that I terminated play at about 5 db less volume than the factory terminated cables. Did I do something wrong in my termination, or is this just the difference in the Neutrik plugs versus the factory plugs? I used Cardas silver solder, and all connections seem good.