Sad to report the demise of the Dayton Audio RSS315HO-44. Parts Express had notified me of a recall involving a 'mass plug' that was not attached well enough and could come loose.
Well it has happened to the Dayton three times now and I finally had to ditch the brand. It seem that the replacements were no better this this regard. PE has been great to work with in helping to resolve this matter.
So I was able to find the RE AUDIO SEX12-V2-4 on PE's site that will drop in (almost) to the box that I made. RE AUDIO gets a lot of unflattering reviews online due to customer service support. I hope my experience is different.