https://g80.bimmerpost.com/forums/sh....php?t=1899742
Note: All its in the attached link including pics and different opinions.
I do think the sound of this sub is very good and quality as expected for JL Audio. I don’t have the specs, honestly I don’t know much of this subject but go to the JL Audio web page-> subs -> microsubs+ (+ means integrated amp). I was thinking of doing the 12’’ but decided to continue with the 10’’ as was the one I have used before. Also google technicpnp; which is a company that sells a connection to add subs to the OEM amp.
Hope this helps