While youthman and others may mean well, haven't found them particularly worth watching. YMMV, I prefer measurements than just a subjective experience of particular parameters. Thus my youtube for audio boils down to Audioholics, audiosciencereview and erin's audio corner....
Port chuffing in extreme circumstances is certainly possible with some subs, but as others have already said....
In any case the Monolith subs have so far shown to be a very good value barring any issues and customer service has changed up somewhat from the early days (where you might have to return a whole sub rather than just trade out amps or something, but believe they've got that going now). Glad to see that europe has a good value sub like the Monolith now (in addition to the others, better than just Rel
).