Bore sizes (HB20 vs. HB21)+(older MW's vs. MW big valve)???

[jon112780]

Why do the horn manufactures do this?

I understand that both the HB20 and HB21 are currently being sold (to great success) @CMC and they both appear to have the same bell and bows. The HB20 has a 'medium' bore of .750 and the HB21 has a 'large' bore of .770- how much difference does a .020 change of bore actually make on these two models? I played a couple of both models and didn't really notice a difference... Did anybody else notice anything?

As far as the Meinl-Weston horns go, I've never played any of the late 90's MW CC's, so I couldn't really tell how the horn has changed. I have played the newer 2145, 2155, 2000 and the 2165 and can only assume that they have all went to the big valves because all these horns (according to the websites) have the same valve set. I've seen post that said the new valves opened up the horn, other posts that said the new valves were too large for their small hands. Anyone out there mind sharing how the horn has changed (for the better) since this change has been made? Say, played a 2155 from a number of years ago (old valves)and played a 2155 made last year?

I was just asking because I thought if I have XXX valve set and could get these valves .040 bigger (but same bows and bell), is it going to make a difference in the volume of sound, or should I just get a different horn?

[cjk]

MW big valves are the same bore as the prior valve sets they were using. Read this:

http://www.meinl-weston.com/pistonvalves.htm

[MartyNeilan]

MW older and large pistons are the same bore, but because the newer pistons are bigger, there is less "overlap" inside them and there are virtually no "dimples" in the ports, caused where one tube crosses over another