To Cut or Not to Cut? (Your Bell.)

I've had some questions about bell cutting and it's pros/ cons and acoustical effect. Here are some thoughts based on my observations. This applies to Geyer designs although the general ideas should be similar with Kruspes. Do NOT cut a bell on a horn that you absolutely love! Some reasons are:

  • Cutting a bell requires the horn to be disassembled and the bell tail removed. This disturbs the connection between the bell tail and first/ short f branch pair as well as between the bell tail and mouthpipe. Since Geyer horns rely on carefully proportioned long solder joints between the aforementioned parts, it would take a miracle to get the horn back together with exactly the same balance. I suppose the effect would be less dramatic if the horn is braced instead.
  • The additional weight at the bell changes the way the horn focuses the sound. By now readers should be familiar enough with my philosophies to know that I am not about to offer a scientific explanation for this. My observations are that the added weight gives more core to the sound and also makes the horn feel "tighter" in the upper range. If left unbalanced, I have also experienced intonation problems.
  • A horn with damage to the bell tail section is very difficult to cut and get a good fit, even in the most experienced hands. Many bell cut jobs are a "best possible job considering the circumstances" deal.

If you want a cut bell, think ahead and have it done before you see it for the first time. There is nothing more disappointing than having a horn you dearly love change...

On the other hand, having a cut bell is GREAT! There are excellent reasons to have a cut bell, for example:

  • TRAVEL! No longer are you begging the stewardess to put the horn in the closet at the front of the plane...
  • Instant access to sound/ response changes. I will post later about bell shapes and alloys, but its pretty amazing to hear and feel the changes that a different bell can make.
  • More focused core to the sound. A properly balanced horn will play better with a cut bell than a single piece. There is something really satisfying about the weight being toward the bell instead of sitting in the valves. I get more power and more control over pitch that way although I can't speak for the designs of others.
  • You can wear the bell like a hat

I prefer working with a cut bell, it makes my life much easier in the construction of the horn and I find the weight to be critical to my design. That is the big reason that I do not charge extra to build the horn with a detachable bell. I do not want people to go with a fixed bell as a cost cutting measure!!

So, I would say that if you are buying a new horn, consider buying a detachable model. Make sure that you know the ring set that is used and how to try or get additional bells. If you already own the horn and are considering cutting the bell, think carefully about how much gnashing of teeth would happen if it changed slightly. If you are in love with, I would pass. However if you are ho-hum about the way it plays, its possible the bell job might even make it play better!


April 5, 2010