Wasn't sure where to post this as I'm not sure what's causing it? Typical scenario: movie ends and credits start, turn down the volume from ref. or near ref. level, notice nasty crackly sort of sound (high freq.) from front left speaker as I'm turning down the volume. Haven't noticed it on CDs but I haven't cranked any CDs lately. Do I need some of the stuff that you spray on the metal stem of the volume control? Seems odd that it's only on the front left channel. FYI: Sony DA333ES receiver (still under warranty) Boston Acoustics Speakers Any help diagnosing this will be much appreciated.