I've put together an ESB-4SC bass kit, put TVJones pickups in it and it sounds great. However, up around the 15th fret and the G and D strings (Bb and F at standard pitch) the frequencies are getting cancelled out, the notes are dying out quickly and not sustaining.
I've checked for truss rod frequency interference, adjusted the angle of the tailpiece, lowered the pickups, raised the string height, filed the frets, nothing seems to alter the muting of those notes. The only other thing I can think of is interference caused by body cavity resonance.
Please let me know if any others had any issues with this particular kit, or if you can offer any suggestions.
with thanks,
Russell