Precision machined from nickel silver, with twice the mass and twice the weight of standard bottom valve caps, Bach heavy valve caps dampen vibrations. The result is a warmer, more powerful sound that is perfect for the concert hall, studio, and club alike. Set of three.
While I had heard that providing more mass to your horn will improve its projection and resonance (without distortion), it wasn't until I bought my first 2 sets of heavy bottom caps. The claims are absolutely correct and it is the reason why I have bought my 3rd set, while planning to buy my 4th (waiting for new stock to arrive).
NOTE: I even added some zinc plated washers at the base of my valves to increase the overall mass even more -- being low cost way of adding mass.
I HIGHLY recommend buying them -- which ever of the 3 types works best for your horn(s).
While I have heard that the overall responsiveness and projection of a horn will improve when mass is added to the bottom to each of the valves (via heavier valve caps), I did not know if this was true.
Having just received a set of these valve caps, I can truly say that they improve the projection of sound so that I can create greater volume without distortion. Based upon the expense, I think these caps are WELL WORTH IT. I would recommend getting them and expect good results -- especially when considering the price.