Currently running Polk RM7500 speakers with an Onkyo TX-DS575 reciever. There seems to be some type of cracks in the sound, high pitched noise that sometimes occurs when im playing a DVD from the DTS soundtrack. This usually occurs during the movie where there arent that many lows and A LOT of highs. Dont think its the speakers, because when i change the audio to Dolby Digital, i dont have it anymore. Might be the amp or the DVD player. I have a JVC 7-Disc XF-XV-FA95GD prog scan player. If anyone has encountered this before or has some tips on how to isolate the problem and take care of it. Basically, anyone with any suggestions would be appriciated , im really desperate to get this problem taken care of ASAP. Thanks so much.