New Gadget...

Dan Schultz · Post by **Dan Schultz** » Fri Dec 03, 2004 8:13 pm

This may be old news to some, but it's news to me! I just bought a tuner called the 'Center Pitch Universal' CP2. It clips onto any part of the horn, violin, etc. and displays what note is being played and if it's sharp or flat dependant on the vibrations of the instrument. It can be used while playing in a group or anywhere that it is very noisy. I'm impressed! I'm going to use it tonight with a German band in a noisey ratskeller. I'll let you know if I'm still impressed tomorrow.

Tubadan · Post by **Tubadan** » Fri Dec 03, 2004 9:54 pm

Here's my theory on the clip on tuners. They register if you're in tune by vibrations of the horn, but wouldn't clipping something to the horn change the vibrations slightly, even if only a few cents? Once you removed it, wouldn't the vibrations change?

Dan Schultz · Post by **Dan Schultz** » Sat Dec 04, 2004 1:46 am

Tubadan wrote:Here's my theory on the clip on tuners. They register if you're in tune by vibrations of the horn, but wouldn't clipping something to the horn change the vibrations slightly, even if only a few cents? Once you removed it, wouldn't the vibrations change?

I can't imagine clipping something with little more mass than a spring clothespin to your horn making much difference. Now... if you want to talk about holding the horn in your lap making a difference... I might tend to agree. Rick Denny could probably explain this much better.

Rick Denney · Post by **Rick Denney** » Mon Dec 06, 2004 10:20 am

TubaTinker wrote:I can't imagine clipping something with little more mass than a spring clothespin to your horn making much difference. Now... if you want to talk about holding the horn in your lap making a difference... I might tend to agree. Rick Denny could probably explain this much better.

I agree. And I also think that clipping things on the instrument won't change the pitch though it may change the tone. Nothing that small would have any audible effect--I feel confident with that statement.

I have a concern about tuners that show a single pitch and its accuracy. The pitch that emanates from the instrument is actually a combination of many frequencies. Audible frequencies of the tuba sound extend across perhaps 12 or 16 harmonic overtones. Each of those overtones colors the waveform, creating difference tones and dissonances that change our perception of their pitch. An overtone that is out of tune can create a beat frequency that might be lower than the base pitch of the note. A range of well-tuned (to each other) upper overtones can create a sense of pitch at odds with the base frequency, even though the buzz is officially in tune. When we consider the interaction of all these various overtones, we realize how hard it is to sense pitch.

As humans, we sense pitch pretty well. But how many times have we heard a note--perhaps played on an organ through a complex range of stops--and we weren't really sure even which octave it was in?

Yesterday, I played at a TubaChristmas, and played the first tuba part on my B&S F. When I played, I heard a high-pitched harmonic that seemed to stand out from the ensemble, and the bottom seemed pulled out of my sound. I didn't like it. But when I play alone, the tone sounds acceptable. It seemed to me that one of my upper harmonics was interacting with someone else's, and probably it was just affecting my own perception, because when we hear our own sound, our perception is colored by the mechanical vibrations that travel through our head.

My concern as this relates to tuners is that I'm not sure how closely tuners perceive pitch compared with humans. I have a frequency-counting digital voltmeter that I used to us to time generator engines to make sure they were putting out the right frequency. But I tried it on my new generator (in my motorhome), and that generator uses an inverter to change the DC output of the generator to AC. The resulting waveform has some upper-harmonic content in it that confuses my frequency counter. Yet, I can plug a cheap flourescent light into the output and tell that the 60Hz frequency is correct by listening to it buzz. It would seem to me that a strobe tuner would tell you about the harmonics as well as the base pitch.

A clip-on tuner perceives pitch one step further removed from the sound. The brass of a tuba vibrates as a result of the vibration of the air within it as we play. But the brass will have its own resonances (rather, impedance) that will affect that vibration in ways that don't necessarily have an audible effect on the sound. It seems like it should be the same, but I wonder if it is in all cases.

Finally, I have a practical concern about using a tuner in any kind of ensemble setting. When I rehearse with a group, I eventually find the slide settings that seem to work best most of the time. I rarely find that I have to reposition my main tuning slide by much. If I'm playing with instruments that are not adjustible, such as a piano, then I'm more careful. But I don't trust a tuner in those situations, because in nearly every case, the pitch to which I need to correspond won't be the one that would please the tuner. Thus, I don't carry a tuner with me. I do use them at home to teach myself a sense of pitch, but often I find myself more confused that helped by them. Maybe if I put out a clean enough tone it would be better, heh, heh.

Rick "who really wants a strobe tuner but won't pay the money" Denney