Hi Protostar1,
I have a very similar space as to the one you are moving into (three walls surrounding a largish listening space opening into a larger area) and have experienced first hand the issues with trying to fill that area with sound.
Receiver/Speaker Problems
Regarding the issues you are encountering with your current set-up, I would investigate the speakers as being the possible source of the problem. The reason I say this is the scraps of information I picked up in reading some reviews associated of that product (ie.
http://hometheaterreview.com/canton-movie-10-mx-ii-home-cinema-system-reviewed/) indicating that there is some kind of protection built into the speakers which try and prevent you from over driving them. It also looks as though the speakers are a combination of being relatively insensitive, requiring lots of power to hit the high volumes and varying impedance (I could only find the specifications of 4 to 8 ohms). The combination of all of the above could be giving your receiver fits.
If you had some other speakers around or that you could borrow that you know are a bit easier to drive (ie higher sensitivity and/or 8ohm impedance), I would recommend swapping them in and seeing if the receiver has the same issue as you approach high volumes.
Unfortunately I can't help out with your subwoofer woes; again if you could find another one that you know is functioning normally that would at least allow you to localize the issue to either the sub or the receiver.
New Speakers
My thoughts would be to buy new speakers first, hook them up to the current receiver and see if the issue with the receiver is on going, and then move onto looking at a new receiver if necessary.
The EMP TEK speakers you have listed are an incredible value; I have no first hand experience, but I have read very little to suggest that you would be dissatisfied with them. I have speakers from the same parent company and have never looked back. Alternatives you could look at would be the Elemental Designs and SVS speaker packages as the discounts appear to be pretty good when bought as a package, and they would include one of their renowned subs.
Other thoughts for the room you are working with would be Axioms M22 bookshelves paired with one of their VP150 centers; the money you would save could go into either surrounds to finish replacing the Cantons or more subwoofer(s). Those bookshelves are amazing units when paired with a good subwoofer.
The issue I have encountered in a similar space to yours is not in filling the room with the mid to high frequencies; the problem with having an opening into a larger area is in getting balanced bass throughout the spectrum without massive humps and dips. Having two good subwoofers and some means of eqing them (like a Behringer Feedback Destroyer, Elemental Designs eQ.2, or similar) would provide for a better listening experience overall. Your choices in subs seem sound; other options to consider would be Epiks' Legend or SVSs' PB10-NSD.
Thoughts on Expansion
The speakers and electronics you have listed would make future expansion hard; your selections (as well as any of the others I discussed above) would create a well balanced system where an upgrade may be hard to do as any noticeable upgrade would start to cost serious $$$. If frequent future upgrades is the route you are set on, my recommendation would be to over kill a component and then work from there.
Two examples of this would be:
- Go light on the towers, center, and surround, and get two of the eD subs (or Epik, SVS, Seaton, Hsu, etc) as that would provide a big improvement for the movie experience. You could then buy mains, center etc as budget allowed and would have less budget spent on the items you would be replacing.
- Go heavy on the front 3 speakers (to noticeably best the EMP TEK E55ti you would probably be looking at a considerable expenditure, potentially double), and get one of the subwoofers from the suppliers mentioned previous. You could pick up a second sub and surrounds in the future as budget allowed.
My personal thoughts on this would be to go with EMP TEK E55ti's and a single sub.... going from a small satellite system to floorstanders is a huge jump (I went from one of Polks satellite systems to the RBH TK-5CT clones from Destination Audio and was blown away by the difference). Getting the second sub in the future along with some form of eq would give you something to save towards and the end product would be better overall then grabbing two smaller subs immediately. Picking up one of the bigger subwoofers would also be a huge jump immediately; the second would be icing on the cake.
Have fun!
Cheers,
Bill