Best musical sub around $1k


Looking for some advices on sub.

I am deciding between Sonus Faber Cremona Auditor + sub or go full range and get Cremona. If I were to go with Auditor + sub, I will need to keep the cost down for my decision to make sense, hence the $1k budget. I like the stregth of mini-monitor - imaging, better coherence (2-way vs. 3-way), and easier placement. But Auditor needs to play loud to sound full range and I don't have that option most of the time due to my power amp (BAT VK-75SE) and small kids. So getting the Auditor will require a sub for my need.

So what sub will you recommend? I had a REL Stadium III before, but price is out of my range right now. Cremona sub is also too expensive. Are the smaller REL as good as Stadium III or I am better off getting an older Stadium (II ?)

Or to complicate the issue further, get a floor standing Cremona instead?
semi
Running a PSB Subsonic 7 here. 330 watt on-board amp, 15" sub. I have it crossed over at around 45hz which picks up where the PSB Silver i's start to really die off.

To be honest, it's really a lot more than I need. Musically, it does quite well down to a reported 25 hz and reproduces heavy bass notes with ease at my listening levels.

Then at $600 (open box return, list at $1k) I think I got a steal.
Try listening to a Boston Accoustics PV1000. Small, powerful and musical... they sell for about $750.00 used and have a nice look to them.
I'll enter a vote for the ACI Titan. It is very musical and Mike D at ACI is a joy to work with
Thanks for the reply so far. I have heard good thing about ACI Titan, but the look is rather unconventional. Will need to check out PSB and Boston Acoustic as well.

Not hearing much about smaller REL like Storm or Strata. I have read before Stadium is where the fun begins, is that true and my money is better spend on other sub instead of smaller REL?