ozboy

[quote=rowuk;366746]. What changes the sound and response is the bell brace and perhaps the bracing on the tuning slide.

I agree with this.

There is a myth about airflow which, when you consider the relatively small quantity of air going through the horn, becomes essentially insignificant!

This is a point of conjecture. Air flow is affected by the venturi created in the leadpipe. This is a major factor in the adjustment of the mouthpiece gap. From my limited understanding, the venturi can affect the airflow through the horn. Horses for courses. Some people prefer the resistant qualities/ airflow of a traditional leadpipe while some prefer reverse. Bracing and other factors also majorly affect but to say the change is essentially insignificant is not a position that I would support. Any change is major. That is why a great horn is a personal thing and why they are so rare.