TubeNet

So I've posted recently about the Mercedes Bach tuba I recently acquired and made a rather interesting discovery tonight.

When I first got it, I tried it with both a regular Helleberg and a 7B and with both mouthpieces it was pretty flat overall. I could get the bugle pretty close, but then all the valve combinations were flat.

Tonight, (and only for a few minutes) I put my clear Kellyberg in and had a go with the tuner and it was amazingly much more in tune! The open bugle was spot on and some pitches that were once flat were now a little sharp (1-2 combos, which can be adjusted with the 1st valve slide). The 2-3 combination was still pretty flat (which I why I'm wanting to trim the 3rd slide), but not as bad as before. 1-3 was almost spot on as well.

Any thoughts at to why that might be? I'm not an expert on mouthpiece shapes, backbores, etc. All I know is that the Kellyberg feels pretty similar to a Helleberg, but not exactly.

Thanks.

If you can measure the distance between the end of the MP going into the receiver and the start of the leadpipe, you may find that distance somewhat different.

That distance makes a big difference in how a horn plays, sometimes more than a change of MP. Changing it is another whole kettle of fish on most horns, usually reserved for pro horn 'tuner' guys..

The Adams euph has an adjustable setting for finding the 'sweet spot'.

You may need to fab up some sort of metal wire with a slight crook in it to find the two 'ledges'.

tuben wrote:What was the temperature of the room and the relative temperature of the tuba during these tests?

It would have/should have been almost identical. I was using the Peterson strobe tuner in the music room where I teach. I keep the tuba at school in my office, so the tuba's and the room's temperature are fairly constant.

Part of the theory about heavy mouthpieces is that the weight increases the resistance. Or as some call it in the context of an oscillating air column: impedance.

I myself like very open mouthpieces, but also the increased resistance of added weight, as it forces (or helps) me to play with more focus resulting in a more intense sound.

Using a light plastic mouthpiece diminishes the resistance, which by some players is experienced as a relief.

I have been around several brass instruments. My first horn was a Hoyer single Bb, quite easy playing, but not with the biggest sound. On that instrument I had a quite long pull of the tuning slide to stay at A=440.

My next horn was a Conn 28D double, much heavier. For months I couldn’t drive it above A=438. I discussed this with one of our foremost professional solo hornists. He warned me against shortening the 28D, as the problem was with me not blowing sufficiently up against the resistance of the 28D. He was right, as I later on had to pull the slide of the 28D to stay at A=440.

We may discuss the reputation of Bach’s tubas, but I doubt they would market instruments designed to play flat, as the costs in guarantee modifications would be prohibitive.

Has it struck you that the problem may be with the intensity and steadiness of your air supply?

Klaus

But, bloke, you also experienced a change in temperature.