So, I've gotten back into playing with with ensembles over the last year and have noticed my tuning slide creeping close to almost completely pushed in to tune to pitch. I'm hoping someone can give me some clues as to what could be affecting pitch, within the limited space of digital text.
Admittedly I have not been practicing as much as I use to, and when I do I have to use a Wick Travel Mute that not only makes the instrument sharp but also crunches the Bb-Bb above the staff octave to a major 7th -without any adjustments. Also back when I was 'in shape' during college the tuning slide was only out maybe an inch, so perhaps I am making a bigger deal out of nothing or simply need to find a way to ditch the mute and focus on long tones. I seem to remember someone in college making a generalized comment about 'players who play flat/sharp are typically doing ____ " technique-wise, but wish I'd written it down in a notebook (and kept it!).
With that said, I did notice a slight difference when I tried different mouthpieces (the tuner confirmed this too). I had moved to a Schilke 52E2 do to liking the larger rim diameter, but perhaps it's just too large and I should switch back to the 51D I used in college. Also I am playing on a Willson 2950 that is nearing 17 years old, and after a number of cleanings and (ab)use maybe it's starting to show some age? That's unlikely to be the case, but the idea of a 'quick fix' with equipment in enticing - NOT the price tag however!
tl;dr - noticing I play quiet flat comparatively, it's most likely me but maybe it really is my equipment?