There are several types of brass most have 59 to 63 % copper and up to 3% lead the balance being zinc. I use 3 different brass types in my endpin designs for cello, though predominantly just 1 type. The differences are audible. I also use rare earth materials in conjunction with the brass and it is these materials that make my endpins more or less reactive to touch and vibration. Specific mix ratios of materials are part of the blend.
Most metric sized brass is c385. Metric sized threads are what holds most domes in place to a tweeter bezel..These are the closest screws to the moving coil and will disturb the flux field of the moving coil if they are steel..which they always are in my experience. You should definitely replace these with non ferrous fasteners..brass is what I know. Brass has between 35 and 70 % slower shear velocity than most commonly used metals.
Low shear metals sound the best in my opinion..other than lead and tin.
There is a very audible difference between using a small steel set screw and one of brass within my endpins. The steel screws the whole sonic balance off and required a total rebuild. Tom
.
Most metric sized brass is c385. Metric sized threads are what holds most domes in place to a tweeter bezel..These are the closest screws to the moving coil and will disturb the flux field of the moving coil if they are steel..which they always are in my experience. You should definitely replace these with non ferrous fasteners..brass is what I know. Brass has between 35 and 70 % slower shear velocity than most commonly used metals.
Low shear metals sound the best in my opinion..other than lead and tin.
There is a very audible difference between using a small steel set screw and one of brass within my endpins. The steel screws the whole sonic balance off and required a total rebuild. Tom
.