Preface... I'm tuned to a E flat, and playing a note in the F postition on the bass. 8th fret on the A string. I'm recording a bass track for my band and after a long while I noticed a warble in the note. The note is the main note that I play in the track. I thought it was the bass and went through every bass I own and it was still there. Whether I play the low "F" on the E string or play the octaves on the A and D strings it warbles on all of them. I trashed a track that was pretty much finished because I thought it was ruined. I just figured out that it is from the speakers that I'm running them, (Yamaha's powered System HSM5 with Subwoofer), through cause through the phones I can't hear it. Maybe it's there but I can't hear it. It's not speaker phase either which I thought it may be. I turned off the right speaker and it was there still. can anyone tell me what is making it warble? I hope this is easy to understand, if not ask me questions. Thanks all, Jim.