KEF Audio Cresta 2 Speaker "denon protect mode 3805" Questions

protect at all times . It was connected to KEF Cresta 1s, cresta2, kef centre and PSW100 . When i took the amp into deneon in the uk, they found no fault and said it could be a speaker problem. I took

...denon 3805 but dont want to risk blowing it if the spakers are to blame. |Is there any way to test the spaekers at home before i go and buy a new amp? i an not very techie Units going into auto ...