mouthpiece measurements

[hyperbolica]

I've recently done a project through my day job which is related to measuring the inside of mouthpieces. I measured the cup, throat and bore for a set of 12 treble instrument mouthpieces. Rim measurements are tough to do, but I got pretty good results on the rest of it. I don't play this particular instrument, but I'm tempted to do the same sort of measurements for all of my trombone mouthpieces. It would be interesting to get actual measurements and inside curve shapes of the ones I like vs the ones I don't care for as much. So many times here we try to describe things without any sort of measurement. Just a lot of hand waving and words. I realize taking the mystery out of things is antithetical to how this forum seems to work, but I'm going to give it a go anyway.

[BPBasso]

What's your thoughts behind the difficulty measuring rims? Where exactly to measure due to rim and cup contour?

[Doug Elliott]

Whether you like something or not is much more about the balance of various parts and how well tbey match to the horn, than any individual shapes and sizes.

[hyperbolica]

What's your thoughts behind the difficulty measuring rims? Where exactly to measure due to rim and cup contour?

If you have a good method you can get good measurements. I'm not worried about measurement method. I'm not that interested in measuring rims at the moment. I might become interested, in which case I might have to develop a new method. I'm sure rim measurement can be done, but it wouldn't be done the way people generally try to do it.

@doug,
I'm more worried about a comparative or predictive standard than the shape, per se. Once I know the characteristics I like most, I just find other mouthpieces with those characteristics, and maybe one aspect different. People now seem to have zero understanding about what shape does to sound. It's all voodoo magic. I'm sure you already know everything I'm going to find out and more, but this is for me. I hate relying on voodoo.

[harrisonreed]

The Vennture VennCAD software already has most trombone mouthpiece makes scanned in to look at in this way.

It's scanned using a tool similar to how the mouthpiece is machined in the first place (x,y coordinates). Very accurate

No voodoo involved or needed

[drpmorris99]

I had a quick play at work over the last week or so getting some profiles from a scanning optical microscope that can do depth profiling, just for interest. Got some reasonable results but as the method is based on focus and mouthpieces tend to be pretty shiny it wasn't perfect. Still, I got this as a comparison between a Wick 6bs and 7cs which have the same rim diameter but differing cup depths...

tmp_1f05e1c9-4956-4367-a010-4eef5570f322.png

the lumps and bumps on the 7cs are artefacts from glare on the surface during the measurement.

Not sure how useful that is for all the reasons given by others, but it was interesting to see the shape and hear the difference! Nice distraction anyways!

[hyperbolica]

My results include 12 plots with very little noise. They are one-sided since the cups are symmetrical. You can see the throat differences and the back bore, although the back bore is all the same shape in this project. The cups range from very U to very V. Throats don't vary much.

I don't plan to do anything with the information I get from bone mpcs aside from entertaining myself.

[jonathanharker]

I've been collecting measurements from various manufacturers over time. Here's a list of what I've got so far, in order of rim diameter. Not everything is on it, and it's mostly just the reported specs (italics is inferred or approximate, usually from a measurement).
https://jon.geek.nz/stuff/mouthpieces.html