Will a new sub sound better than my Velodyne F1200?

+1 hgl3. I must confess to being a Velodyne whore beginning with their FSR 15 more recently the DD18 now using two DD 12 Plus'.  

But for now if adjusting the phase helped try switching the polarity. I have found some recordings with polarity differences from track to track thats noticeable in the Kick drum. Assuming the SMS has remote control and EQ presets set one to the different polarity.

I purchased one of my 12s from (I found out later) the worst third party dealer on the East coast and the other from Velodyne direct. The inferred receiver went out on the third party unit. Since Morgan Hill is just over the hill from Capitola I hand delivered it for service and it was done the next day for a ridiculously low fee.

I was fortunate to have on loan a beautifully wood crafted in the UK REL Studio III, the then newish auto EQd JL Audio F113 and my two year old DD 18 in my home at the same time. Both the REL and the JL benefited from being fed multi band EQd signal from the Velodyne. I think JL now offers multi band and REL has even nicer looking cabinets. I don't get REL at all, but hey.    

Velodyne also now makes sensors for autonomous systems.  

I'm convinced that multiple subs is superior, but I'm completely out of room on my front wall, and I don't have front corners to place the subs in. For two subs, I'd have to put one on the front wall and the other on the back wall or a back corner. I agree Bob, that two HSU units would probably be preferable to a single SVS 16.

I think one of my integration issues is that my mains aren't high-passed. With the ports plugged, they start to roll off around 80hz but it's a very gentle 5db/octave rolloff at that point, and then there is probably a 12db/octave rolloff around 55hz. There is a LOT of overlap, and both the mains and the sub show a big room node at 60hz. 

Does anyone have recommendations for good XLR high pass for my mains? I don't want the signal quality to the mains degraded in any way.

I'v used the Velodyne F1500 for 25 years for movies.
The F1500 uses a 15 inch woofer and a built in amp.
My system is Canton Ergo 90 speakers, Canton center channel and Canton rear channel.  The F1500 is an amazing sub.   I wouldn't use it for music, but for movies its incredible.  I bought it in 1992 in Harvey's electronics in NY.
I remember Harvey's would play the Infinity SSW-210 Sub which was Infinity's top Servo sub for movies back in 1992.  The infinity SSW-210 used two 10 inch woofers and a built in 250 watt amp. 
The infinity was good for movies, but the Velodyne was superior for movies.  

The only problem with the F1500 and F1200 Velodyne completely abandoned any support for their early drivers that were made in house.
I never heard the F1200, but i know it was the Velodyne sub below the F1500
If its anything like the F1500, it should be good for movies. 
My only regret was i should have bought a backup 15 inch woofer for the F1500.