Slide adjustment by instrument

[pickupleftoff]

Something I have been wondering about lately is how certain trombones need to adjust for the typical partial tendencies while others need less or seemingly none. For example my horn seems to be almost equally flat on the D partial as it is the F partial. I've even heard that a certain brand's horn doesn't need and adjusting at all.

With my very limited knowledge of the harmonic series I don't understand how this could differ horn to horn. Does anyone have any input on this?

Thanks!

[Doug Elliott]

Certain parts of the horn, especially the tapers such as the tuning slide, can be adjusted in various ways that influence the intonation of the harmonic series.

A straight tube closed at one end (by your mouth) with no mouthpiece or bell will resonate only odd n\umbered harmonics 1, 3, 5, 7, 9 etc. The mouthpiece and bell compress that widely spaced harmonic series until it sounds like the normal harmonic series. That's why the overall design is important, and how it can be adjusted.

[sirisobhakya]

As far as I have tried, EVERY horn has to be adjusted for. Horns from a same brand usually have similar tendency though. For example I have to adjust in the same way on my YBL-830, YBL-612R, and YSL-820GII, but every Bachs I have tried has to be adjusted for differently.

I think it lies mainly in the bell profile design, since theoretically the bell is responsible for raising harmonics. Bore profile also contributes, therefore some say dual bore slide has different harmonic series placement from single bore slide. (Same as Doug said above.)

[Finetales]

Where the braces are can make a difference too.

[Burgerbob]

Every 3B I've owned has been completely different.