Openbox v8s .... Sound /audio problem .

Hi there
the brother got an openbox V8S at the weekend and although for a cheap box it does the trick there is one annoying problem , the sound sometimes gets distorted / muffled . i have set it up in my house to see if i can figure out whats up with it as it dosent happen all the time . sometimes if you change a channel especially the *** ones the sound is muffled and distorted and the only way to get the sound clear is to reboot the box . i have looked at the audio settings but nothing seems to work bar rebooting the box . the box is brand new . Any Ideas what the problem is and how to fix it and has anyone else had this problem ...thanks

H imaazkhan9869
i am using HDMI although the box has the scart option . The picture is alot better with HDMI as alot of the channels are in full hd .

OK thats worth a try although the one i am using is brand new that came with it but it might be a cheap brand...i will try that , cheers buddy...Apoligies as i didnt notice until now that you have an Openbox V8S ...