Honestly, I think you should return the subwoofers as there's no reason to settle. You spend your money and you should be satisfied with your purchase. You tried all options to make these subwoofers work. It's just not meant to be
You should provide the ML rep with the serial number of 6 subs to see when they were manufactured. If it is a bad lot, then ML can narrow down the quality control issue
Hi,
I own 2 1100x and I have not had any problems. I even own a 800x with no problems. The subwoofers are two years. This is an unfortunate situation. Dynamo 1100X is an amazing subwoofer. I hope you are able to find a solution