Let me guess, you have a passive bass or a passive pickup and active pre-amp. Your bass needs a shielding job.
The buzz is the pickups getting outside interference, it is worse in some rooms than others. If you have a buzz that gets louder when you touch the metal/strings/bridge you have a grounding issue. If the buzz goes away when you touch the metal/strings/bridge you have a shielding issue.
This is a fairly common problem, that most people say cannot be fixed. It can.
Find a good shielding guide on tb here, it is a fairly easy process. Since it will call for copper foil tape, you can source it locally from stained glass supply shops, everything else required is fairly common.
If you have any questions feel free to PM me, I have a lot of experience with shielding and I refuse to play a bass that hums, so I get why others refuse to play them as well.
Carvin LB76 / Dingwall ABZ ! Support Local !
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Epifani UL2-310 / fEARful 1212/6
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