Originally Posted by
mandocello8
Thank you for all the replies.
1) "it's the other strings" : I am pretty sure we muted the other strings but I will recheck. the ghost tone is slightly off from the open-A frequency.
2) "setup" : setup from the factory is pretty good, bridge position and intonation are correct. action at the nut can come down a bit and neck relief needs small adjustment (there is a truss rod). both mandolin luthier experts in town (vancouver bc), are quite busy and have long wait time (weeks, months). this mandolin will visit them sooner or later.
3) "applying mass to the top and or back" : assuming it is an unwanted body resonance, would this only shift the frequency or kill it completely? the physics can go both ways. if frequency is shifted to exact A 440/880 Hz the owner may be happy (until they play tunes in Bflat). I am not sure how much experience our local experts have with such problems.