My concern was will I be able to tell the difference between a $350 sub and a $1100 sub and leads me to another question.
Yes.
My first (home) sub was a ~$300 Kenwood 10", 400W sub. Your typical mass-market big-box store sub. I was amazed at the thump and bass that it would put out when it was paired with a set of full-range speakers. A couple of years later, I bought some smaller bookshelves, and had a heck of a time getting any sort of midrange warmth in my system. I bought M22's to try to remedy it. Helped, but still really cold.
By that time I was looking to this group for advice, and several people recommended that I dump the Kenwood and get a "real" sub. I did my research and bought on an $800 SVS PCi+ 12" 20-39. Blew. My. Mind. It completely changed my system. I had no idea how much upper bass warmth and lower-bass punch & impact I was missing, and how much that added to both movies and music. Movie explosions changed from just being this loud boom/rumble to actually having dimension and nuances to it. And the power, holy moly. I've actually managed to break my house* with the power of this SVS sub.
The most chilling demonstration came when playing Yo Yo Ma - his cello simply
came to life in my living room. All those low frequency harmonics that my old sub couldn't produce were now present. Stunning. It nearly brought tears to my eyes.
A sub may only really "stand out" when watching a movie, but I say that they make a pretty serious difference just in music too. Absolutely ZERO regrets in buying that sub. Other than being curious as to how much better an even MORE expensive sub would be.
So yes, put some money into a good sub. It's worth it and you will be able to tell the difference. Since this is an Axiom forum, of course you're going to get a lot of recommendations on Axiom's subs. The EP500 & EP600 are said to be amazing. I have not heard either. If you feel you need an all-Axiom system, by all means, get one and be content knowing you've got one of the best subs on the market.
But there are always other options. I'm completely happy with my SVS sub. And HSU Research is another one you should look into. As with Axiom, both HSU and SVS make subs that offer tremendous value for the money.
Good luck!
*Seriously. My home has old casement windows that have weights behind the walls attached to ropes to help open/close the windows. I've had several of those ropes snap during LOUD sub passages.
