[quote name='bozzbass' post='482847' date='May 8 2009, 12:10 PM']Sorry, do you mean 7th fret on a low string tuned to E or B? Either way it sounds pretty good as that area of the neck sounds the best for using an octaver to my ear.[/quote]
Realistically about 5th fret on the A, give the right patch is about as low as you will go, and that will be stretching it.