I prefer using line level with any sub that I have owned. Some prefer speaker level. It all depends on the main speakers that you are using with the sub.
REL has been around for 30 years so I would not call it a current fad!
https://rel.net/our-story/
REL has been around for 30 years so I would not call it a current fad!
https://rel.net/our-story/