Subwoofer Advice & Therapy :)

@ohlala is absolutely right. Placement is paramount. But that's where phase helps a lot. Adjustable phase, esp with more than one sub, makes additional positions possible. We all have to work within the constraints of our rooms, furniture, etc. Adjustable phase plus placement gets you closer to optimal integration without having to put things in (possibly) crazy places in the room to deal with modes.

@norust       The other tradeoffs I know exist are in regards to the position of the sub and the size of my listening room. I only have one front corner location (with some room between the back and side wall). 

Welcome to the Gon and more importantly to the Deep End.

With room positioning being the most important first step I'd bank the simple crawl test would reveal a standing wave bass mode near your available side wall location. 

The crawl process takes the trial and error out of moving heavy things and would reveal all your rooms bass mode best subwoofer locations. It only need be done once so map them out for the future.

With a 30 day trial and what looks to be the most comprehensive remote processing on your short list the Arendal just might be the smart choice. All the best in your search.

Well, since you’re in research mode maybe take a look at a pair of SVS SB1000 Pro subs. Before you panic, these are only around 13” square so visually unimposing yet will still get you down to 20Hz (-3dB) and include integration software. Most people here much prefer two subs to one and for very good reason, so if you can possibly sell two small subs over one bigger one to the wifeboss I’d at least give it a go. Another plus is that a pair can be had for as little as $1150 (depending on finish) and come with a 45-day and totally risk-free in home trial that includes shipping both ways.

https://www.svsound.com/products/sb-1000-pro-subwoofer

If ya gotta go one sub I’ll reiterate looking at the Rhythmic F12G (the one with the paper cone) and buying a used DSpeaker integration device like this one (retails for $1199 so at $600 or less here it’s a good value IMHO), but at upwards of 16” square the Rhythmik could actually be more visually imposing than the SVS subs — always trade offs.

https://www.ebay.com/itm/145216049992

Rhythmic subs offer very high performance/$ but lack integration software hence the DSpeaker unit, which is excellent, and you’ll still be under $1800 for both.

That said, I think you’d be very happy with a JL Audio sub as well although it’s relatively a bit pricier, and the Arendal sub looks very interesting as well but I’m just not familiar with it.  I don’t consider the REL T9/x to be a true subwoofer as it’s down 6dB at 27Hz so it’s more like a regular woofer, and there’s very important musical content below 30Hz that can provide significant improvements in areas like imaging and an expanded soundstage (subs are not just about added bass — not by a long shot). Anyhoo, as you’re in research mode I thought I’d just give you more options/info to chew on and hope it helps at least somewhat. And welcome to Audiogon! Great to have you here.