Currently running an SVS SB-1000 Pro and though I'm generally pleased with it, I'm beginning to feel like it might be a bit underpowered for my space (about 3500 cu ft).

My first thought was to pick up a second one (since I've heard nothing but good things about going to dual sub) but I'm wondering if it's the right path forward over just moving to a more powerful single unit. My setup is as much a living room as it is a home theater and I don't really have a ton of placement opportunities for a second sub - there's honestly only 1 possible spot (2 if I'm really desperate) it could go and I haven't done any testing to see if it even makes any sense sonically. If this is truly the best way forward I can try to make things work but I'm starting to wonder if selling the SB-1000 and just upgrading is better given my placement constraints and the volume of air I'm trying to pressurize with smaller sealed subs.

I use the setup for a good mix of movies and music, though if I had to choose one to buy for I would go movies - I'm assuming that means going ported sub.

My ideal budget would be around $1000, though I could stretch closer to $1500 if need be. I would want this price to be all-in though, so if I'm getting into the territory where people will start suggesting doing extra stuff like picking up a miniDSP and setting up BassEQ & all that I'd like to factor it into the cost. Been looking into offerings from SVS, HSU and Rythmik - also open to going the DIY route.

Thoughts?