Thanks for the topic sparksgja
Following my own advice (see topic "Happy Holidays and Your Favorite Tips?) ... I consulted with a long time subwoofer builder who has great passion around the topic, also others having formidable experience. I was guided to a Rythmic Direct Servo sealed L12 for my purist 2 channel small studio. Still selling at a delivered price of $629, it integrates seamlessly with my super quick monitors, digs into the low 20's and abounds in musicality. I found one well-placed sub superior to having two, in my system. Money saved can be applied to bass traps. Bonne chance.
More Peace and Joy Pin (bold print for old eyes)