Sabrina X Anyone Add Subwoofer(s)

IMO and based on my experience with the original Sabrina, I would wait, get them in and give them few hundreds hours of break in time. If possible have your dealer set the speakers up for you if they’re trained to do so by Wilson Audio. If your room isn’t acoustically optimized you might want to consider getting that done. Subwoofer would be the last thing to worry about. These speakers have pretty good bass on their own plus properly integrating a sub is usually a PIA. 

Wilson uses their subs with the Alexandrias, so what does that tell you?  My advice, get two smaller subs — you’ll get much better performance.  

Smaller subs .. Do you have specific speakers in mind?

For example REL suggest their S/812 as a mono sub, or S/510 as a dual.  The smaller T9x doesn't have the low end extension needed.  My dealer carries the 12" Fathom v2, but at $5k it would be a single sub in my system.

If going with REL, these are the recommendations for Wilson Sabrina on their Web page calculator.

Small room :  S/510

Medium room : S/812

Smaller subs .. Do you have specific speakers in mind?

Well, an easy solution would be a pair of JL Labs smaller subs like the E-Sub E112s that’ll still get you down to an honest 22Hz and cost $4600 for both. There’s also the excellent Rhythmic F12PEQ that would also cost around $5k for a pair, and obviously Rel is another viable option depending on your preferred sub connection type. In any case, I’d highly recommend doing any of these options over buying one $5k sub. Hope this helps, and best of luck.