I was looking high quality sub to add Kef ls50 wireless without spoiling image of kef sound and my intention to use only for movies or some times for music listening if i want feel like concert like big bold sound. I knew, needed something like room correction sub and app control required as i had experience with other brand room correction sub. So i tried Dynamo 800x from audio advice. i left with great disappointment after playing while with different settings, Mobile ARC nothing worked out . there was huge vibration on floor ( wood carpet 1st floor ) without out tight musical bass and feel in my gut . if i increase volume it sounded like ported sub woofer especially with movies . Even i waited for 3 weeks for break in period and no significant improvements . so i decided to try 1100x , gland i did. exactly this is the what my expectation were in my mind, when was searching sub woofer . With 1100x i am able to hear difference in bass musicality. Sound is very very musical with fast thump feel in my gut, big and dynamic tight bass even at moderate main volume of Kef without any vibration on floor (80hz crossover and -14 db sub with Mobile ARC ) . I saw The Ritual, quiet place, The Greatest show man trough app tv , All theses sounded great especially in ritual movie after they enter forest , there was thunder sound and that sound almost reaches near to life-like real thunder sound. From this experience i can strongly recommend that do not go for 800x and just go for 1100x there is a huge step up between 800x and 1100X. i can say simply 1100x performance matches the production description what ever they mentioned.