Small room sub: PSB 350 or Martin Logan 800X?

I’m looking to upgrade a small ported 8" powered sub with a new one. Here are the details:

- 8 X 14 room
- front corner only placement option
- sealed much preferred
- speaker-level input needed

Anyone have experience with the PSB 350 or Martin Logan 800X? I like the ability to tune with a phone via ML, but I'm most concerned about ultimate sound quality over setup convenience.

Thanks for any suggestions between these or any other that has the features I need.