Your sub experience: Easy or hard?

Piece of cake integrating Hsu VTF-2 Mk 4 with Eminent Technology ET 8.and in my TV system with JBL Hartsfield.

As well as plumbing the depths, the sub will benefit yr system by relieving yr mains of lower octave duties. Yr mains will play more relaxed and bloom. 

Hsu no longer makes the VTF-2 which had a downward firing 12 inch driver. I preferred it to a forward firing Hsu with 15 inch driver. e.g. on Kill Bill Vol. 1 you can feel the head as it hits the table. And I do mean feel.

I use a single REL SHO S/5 in a very irregular room, H/W/L all vary. By necessity set up is behind the tv and took only a few tries for great sound. Close to the wall and aimed to a 45 degree fireplace two feet away. Here’s the bizarre part. Just last week I experimented with rotating the speakers for zero toe in, same position. No bass. Cranking the sub produced nothing but distortion. Weird. Toed them back in and all is well.

It was hard until I got some furniture sliders.

I integrated four SVS SB16 Ultras with LaScalas, phase aligned and EQ'd using REW in three or four hours.  There was a bit of a learning curve with REW so I think I could do it much quicker a second time. 

I use the REL Stentor III and I've also used their Stadium model. Both use a Speakon connection to my amplifier's output taps, along with my regular speakers. Integration has always been easy and seamless, as the amp sends only a small signal to the sub. There is an "overlap" of some of the higher bass frequencies, but I believe this contributes to the seamless integration I enjoy. I control the crossover point and the volume, and the placement on this "sub-bass" is typically where it provides the strongest signal. This is often the opposite placement as for traditional subs, and it's perfect for fitting it into a non-dedicated room: against a wall, or even in a corner is perfect.