No can understand....

I have a Denon AVR X3100 and have set it up using their setup preceedures (very easy).....I have the speakers in a 5.1 surround sound configuration. Anyway, often the dialogue is so fuzzy: blurry, its very difficult to even understand it’s English. (I should have revealed that the speakers are floor standing NHT speakers on the left and right,with an NHT center and in ceiling speakers (don’t know the brand) for the 2 rears) and Outlaw Audio sub. There is a graphic equalizer, (not much help) and there is a dialogue boost/cut (likewise not much help). I'm using midlevel Wireworld HDMI cables..... Any suggestions?

I'm not familiar with your particular HT receiver, however I'm sure it is adequate to give you good SQ and dialog. The NHT center should be OK too. I'm thinking you have a setup issue. Can you go back after running the setup procedure and check to see what the setting are actually set at? Also, curious if you have gone into your source to insure it is set up correctly. Are you having the issue with DVD, Cable TV box, etc? Are all of them exhibiting the same crappy SQ or is it just from one of the sources?

If its all of the sources, the issue is likely in your receiver. If it sounds bad after running the setup procedure, it might be defective. Have you tried resetting the receiver to factory defaults before running the setup? You might even want to listen to it set to factory defaults without running the setup to see if it still sounds bad.

Hope you figure it out quickly. I know it can be frustrating........

If your receiver permits manual entry of speaker distance and sound level, you might try the time honored tape measure and Radio Shack SPL meter, using pink noise from a disc if your AVR doesn't provide it.  You'll be in good company; some high-end processors do not provide automatic setup, relying instead on tape and SPL meter.