Changed to Obligatos from helicore hybrids. Liked the varm sound and smooth feel from the Obligatos but the Bb on the G-string and the G on the E-string buzzzzzezz like crazy. Thats makes me realy sad. I took the bass to a violinmaker here in my town, stayed there for three hour. What did he do? changed the position of the soundpost.... Was it better after that? NO! I dont know of any luthier with bass-knowledge in my area. So.. what is my question? I dont know, maybe you know what cause this buzzzzzzz or what ever / Hey Hopp
I don't know much about the helicores but when I first switched from spirocore orchs to obligatos, I had a powerful buzz on the A. I took it to my luthier and after about 15 minutes with a plane and straightedge the buzz was gone. The obligatos have a wider vibration that some strings so they could be buzzing on a high spot on your fingerboard. You probably need to seek the services of a real bass luthier. There are several regular TB posters who are from Sweden. You might contact a few of them and see if they can recommend anyone.
Obligatos are flabby. My bass was set up originally for them and, even then, I had to play them fairly high to prevent buzzing. I have my flexocors practically laying on the fb and they don't buzz at all.