The WPC figure is only rated for 2ch. For 4ch it'll be lower.
In any case it's been said n times it's pointless to do it. Read this.
Audiosceptics accept audio trials using 25 people. A recent Oxford study with over 353,000 patient records from 639 separate clinical trials shows for every 1,000 people taking diclofenac or ibuprofen there would be 3 additional heart attacks, 4 more cases of heart failure and 1 death every year.
2015 Denon AVR thread ----> http://www.avsforum.com/forum/90-rec...dcp-2-2-a.html
Think your AVR is defective? Check the Owner's manual and do a factory reset 4-5 times if necessary.