Dan, I have heard Dynaudio speaker with lesser electronics before and they just don't sound as good as they should. The issue is especially true if you plan on using a surround receiver. When all five speakers are going, there just isn't enough clean power being deliver to the main speakers.
Croos over to a high quality powered sub at 50-60Hz will solve the amp power issue, but you will also need a good digital processor with very clean bass management.
So the best way to go would be to have a good CD/DVD transport sending a digital signal to the surround processor and have the surround processor to adjust the cross over. Some of the newer surround pre/pros have variable digital bass management that can even solve bass loading problem. Check out B&K Ref50 or Anthem AVM20 or the newer Rotel pre/pro. I think the Rotel receiver can only do a fixed cross over at 80Hz and it might not be done in the digital domain.
The other option is go with a dedicated amp and just use the receiver as a preamp. You can pick up an used McCormack DNA or Aragon 4004/8008 for $1k. You can get have the cake and eat it too.
Croos over to a high quality powered sub at 50-60Hz will solve the amp power issue, but you will also need a good digital processor with very clean bass management.
So the best way to go would be to have a good CD/DVD transport sending a digital signal to the surround processor and have the surround processor to adjust the cross over. Some of the newer surround pre/pros have variable digital bass management that can even solve bass loading problem. Check out B&K Ref50 or Anthem AVM20 or the newer Rotel pre/pro. I think the Rotel receiver can only do a fixed cross over at 80Hz and it might not be done in the digital domain.
The other option is go with a dedicated amp and just use the receiver as a preamp. You can pick up an used McCormack DNA or Aragon 4004/8008 for $1k. You can get have the cake and eat it too.