I came back to the forums to answer an older post I made asking if I could hardwire two 700 subwoofers to my soundbar 700 but the post was locked. The answer is yes you can! All you need is a 3.5mm audio splitter and it works perfectly. The sound quality of the hardwired subs is superior to the wireless setup. If it is convenient for you to connect your subwoofer, it's highly recommended! The cables are cheap, so what do you have to lose in testing it and deciding for yourself.
Just note, it may not balance perfectly using the AdaptIQ calibration.
When you have two Bass modules connected it will send different signals to each depending on where they are placed and other products in the room. Using the splitter will treat both as a single Bass module and this may affect sound quality.
Saying that the quality could still be good, just not the best it can be.