sleeving the 4th valve slide on Holton 345 or 2165

[cjk]

The 4th valve on Holton 345 tubas has a larger bore than the first three. The Meinl-Weston "big valve" set is like this as well (1->3 is .748, 4th is .787). On a small tuba, this often would seem to help the response of the low register. On a big tuba, it seems to take too much resistance away and makes the low register a bit less responsive.

I have heard that some folks have sleeved the 4th valve tubing on Holtons and MW2165s. This would effectively add some additional resistance to the 4th valve notes, potentially even improving response a bit down there.

I am assuming that slide tubing that fits inside the 4th valve tuning slides is used. I mean that it ends up fitting like slide tubing inside of the tuning slide tubing. I'm also assuming that it would just "step down" the bore of the 4th valve tubing back to .750 in some spots but not throughout the entire slide.

I am interested in specifics on how something like this was implemented in any particular case.

Things like:

* How long a piece (or pieces) of tubing was (were) used?
* How many pieces were used?
* Was just one piece used or were several?
* Were both 4th valve slides sleeved, or just one?
* If just one, which one?

If you do not know the specifics of what was done but you know someone who has done it, I would appreciate it if you would please PM me their name and any contact information you might have.


Thanks,

Christian Klein

[imperialbari]

You are entering a very problematic topic alone for technically reasons.

You impossibly can sleeve all of the 4th valve tubing. Depending on the length of and the number of sleeves you will introduce reverse stepwise reductions of bore. These reverse steps will create turbulences if these steps are not carefully bevelled.

There is a commercial plastic product allegedly directed towards needs like yours. I don’t remember the name (and I consider it a rip-off solely benefiting the purse of the person marketing it).

My approach first of all is about not choosing instruments causing such problems for a specific player. My second measure is about choosing a mouthpiece with cup, throat, and backbore giving the right resistance over the full range.

In general I have to open up backbores to diminish resistance of the low range.

Klaus

[CC]

Christian,
I know exactly what you're talking about. This goes along the lines of horn players adding match sticks at various points inside slides to create turbulance/resistance therefore altering certain aspects of their instruments artificially. I've done this on horns in the past using tubing and through blind tests determined that it DOES have an effect. This effect however varies greatly from instrument to instrument and is why we've seen some commercial products (i.e. Acousticoil) being introduced over the years.

I know of SEVERAL well established players that would experiment with different lengths of tubing inside the fourth valve tubing to play around with this phenomenon. They have gone as far as to having tubes in ALL of the tubing in the 4th or as little as a shorter piece in the bottom slide. You should try this if you are really interested in experimenting. You should also know that this may not have any effect at all on your horn or even make things worse (in terms of too much resistance). No special repairman is needed to make these tubes work with your horn, just be sure to get tubing that is quite a bit smaller and place them in the slides, and DO NOT FORCE things when moving the slides in and out.

I do not know the exact physics behind the phenomenon nor do I feel I really have to in order to appreciate the differences that occur. All that matters to me is the sound. I've experimented with this practice and found that my personal horn is better without it. So - Try it and find out, besides it's worth learning about no matter what some may say. If you want to chat about it, feel free to give me a call - just send me an email and we can talk.

All the best