The Four Laws of Horn Resistance

A primary goal of my designs is to make the resistance of a double horn change considerably less than a traditional design. To do this we must acknowledge the following rules that affect all brass instruments:

Law #1. Given two tubes of the same diameter, the tube that is longer will be more resistant than the shorter tube.

Law #2. Given two tubes of the same length, the larger diameter tube will have less resistance.

Law #3. Given two tubes of equal length and bore, the one with tighter bends will be more resistant.

Law #4. A heavier horn will respond slower than a lighter horn and will hold its basic tone to a higher dynamic. Also, it will feel more secure but be harder to play at soft dynamics. A lighter horn speaks faster and changes color more quickly but will feel less secure. It will be easier to play at soft dynamics and require less effort to play overall.

While these laws are simple, the process of combining different degrees of these laws can create a limitless amount of variation. 

One of my primary goals in new designs is to try to reduce the difference in resistance between various fingerings. An example of this is the difference in resistance between the F horn and the Bb horn. 

This is because of law #1 – the longer F horn (148”) is more resistant than the shorter Bb horn (106”) keeping in mind that the two horns are the same bore. 

To counteract this undesirable effect, I make the entire F horn a larger bore. This is using law #2 to neutralize the problem of law #1. Another way to counteract the greater resistance of the F horn is to add resistance to the Bb horn by making tighter bends. In this case we are using law #3 to neutralize law #1. This second method is a common practice for most horn makers.

Another common issue for horn players is the avoidance of using Bb-23 on a high Ab at fortissimo. Most players won’t use this fingering because it often sounds edgy and feels insecure. Yet, if that high Ab is the fifth of a chord it needs to be sharp. That is essentially impossible to do with a Bb-2 fingering. When using a Bb-23 fingering you are adding a major third to your horn’s length and you are adding a significant amount of resistance as well. By making the Bb-3 slide a larger bore and reducing the bends we are reducing the change in resistance thus, making this fingering combination a useable option.

Through experimentation, I have chosen to make all my F-1 slides .004” larger bore and the F-3 slides .008” larger than the F bore. That F-side bore can vary with each client but is typically .476”.  So, the F-1 Slide is .480” and the F-3 slide is .484”. While this does not completely even out the differences in resistance, it does make a substantial difference in evening out the horn without noticeable tone color shift. 

I use the same principles on the Bb horn as well. The overall bore that I use is .468” The Bb-1 slide is .004” larger at .472” and the Bb-3 slide is .008” larger at .476”. I don’t expand the second slide bows because they are quite short and don’t alter the resistance as much as the first and third slides do.