I think we will need more details -
Have you checked other speakers or receiver to find where the issue is?
Is this with any music or all movies, or anything particular?
Is it from all sources on the receiver?
What steps have you taken to find and fix this cracking sound?
Have you checked the cables?
Is it on all channels?
Is there any processing in the AV? Is it better or worse?
Is it coming from speakers or subwoofer?
Is the sound (crackle) coming from speaker or subwoofer cabinet, or the driver?
Have you checked the gain settings on the reciever?
Perhaps you are getting my drift to be a bit more specific and provide objective details. You will get more helpful replies than by stating you are not happy with the sound or there is crackling at 67. Hope this helps!