Aerial model 5 woofer replacement

Why wouldn't you call an Aerial?  They likely have some spares.

I second the recommendation from @hk_fan.

I spoke with Michael Kelly within the past year and, while they did move locations, the business is still operational.  Michael is one of the good guys I have purchased from and very helpful to his customers, IME.  It would be silly to get your replacement driver from anywhere else. 

I agree, although I ended up not buying Aerials, my conversationS with Michael would lead me to believe that he would be most welcoming to the opportunity to help.