| To add to what trickg has correctly stated, I personally find most add-on to be somewhat gimmicky and often give something, but take away something else.
I had a large bore Bach 72/43 that I bought used. It had had the brace from the leadpipe to the pipe leading into the 3rd valve removed. I thought it just great that way for 13 years until a friend asked me to try the moveable sound post he had on one of his horns. I "humored" him and put it where you could see where the old brace was. The improvement was amazing and for the better! It tightened the horn up a bit and made upstairs less of a blow. I bought the brace from him and moved it about 1/4 inch closer to the one on the tuning slide and left it there.
I ended up trading that large bore to my friend for a Vindabona. He moved the brace slight back from my "ideal" spot and has left it right there.
This brace likely worked because the horn was designed for a post where one had been removed, but it does show the posts do do something and it was enlightening to see how the horn was changing when the post was moved even a little bit. |