Your sub experience: Easy or hard?

I'm running two JL Audio F110s with auto room optimization, which is the main reason I say sub setup is very easy. The JLs are active and non-ported so they work pretty much anywhere I put them. The ARO adjusts for room modes. I also run a JL Audio CR1 active crossover to set the LPF & HPF, which I think is also a reason why my subs are so easy to integrate. My speakers are Magico Mini MkII, which sound great on their own but the subs add a lot of dimensionality and grip. 10/10 would recommend. 

Great topic. 

I have been running 2 REL T9is for a few years.  Setup, now, is a breeze.  I could turn them off and reset them and have them integrated again in 15-20 minutes or so. At first, however, I had trouble because I kept fussing with them.  As I gained more experience, I picked up more intuition and my ear got better trained. 

Disclaimer--I only use them to bring out the lower octave or so. I have them tuned so they are not particularly audible.  

The difference with the subs is remarkable and I would never go back to not using them in this setup. 

Gotta point out that choice of sub used is key. The right sub is one that is designed to supplement your mains as needed. If monitors with limited extension you might get away with a smaller sub needed to fill in the low end well. If larger near full range speakers you will need a bigger more extended sub to do that. Room size also matters. The bigger the room the bigger the sub needed. Sub should have level and roll off adjustments at minimum. Phase is a big help for placement flexibility. Very important to look at sub frequency response specs to identify good candidates. It’s almost always about filling in the missing low end. So be sure to lock the right solution for the problem which is different case by case. From there it is not hard. Otherwise, may be impossible.   To get good bass more consistently across the room multiple subs might be needed.  For just the “sweet spot” just one may do fine.  Gotta have the right overall integrated design to start.  I suppose that part can be somewhat hard. Good luck !

Easiest and most significant impact to SQ, to date. Started with a single REL Carbon Special. Returned it because I had to keep adjusting the gain. I could not find a one size fits all setting for my exacting taste. I tried a REL 212SX next and I barely had to touch the crossover and gain controls. It was dialed-in within a few diverse tracks. Now I own a pair of 212SX and will never live without subs again. I have towed one of my 212s to audiophile friend’s homes and blew them away with the improved mids and overall depth of stage. These are friends with Wilson Sasha DAW, Dynaudio Confidence 60 and Focal Scala Utopia EVO. Subs were a definitive lesson for me and my circle. I saved a ton of money and chose a smaller main speaker there is no argument I am missing anything compared to any other system I’ve heard with speakers costing way more than my subs and mains combined. If you did not hear it above, a single 212 was basically plug and play. No joke. A pair are heaven in my room.

Moderate: Stereo pair, locate near mains, phase 0. Took some time and effort listening to a variety of music to get the gain and crossover dialed in.