new synchrony 1bookshelf one louder than the other

dear friends ,

i have only last week bought the synchrony 1b bookshelves i ran them for about appx 50 hrs at low volumes to break in before i started to actually sat down to listen to them and when i did , it seems that one speaker is louder than the other as the image shifts to the side that i place the speaker in , all other parameters remaining the same

i have the nad 175 pre and nad t 793 power amp
before breaking in to the speakers i did the audyssey set up which set the right speaker to 2 db more than the left
distance set was the same for both the speakers

any solution to this also if i were to only to play music to the one speaker which is softer for another 5-10 hours just by itself will this help to balance the speakers or is this a manufacturing defect

thanking all in advance

thanks jakewash

but on going through my entire set up wherein the i have biwired the speaker on of the connectors were loose , every thing is working just fine now

regards

faiz