Variable cup depth with spacer ring

[heinzgries]

I used a 3D printer to make a spacer ring to adjust the cup depth on a mouthpiece with a screw-rim.

[ghmerrill]

Aside from other questions about this, wouldn't using an O-ring have been simpler?

[timothy42b]

You can adjust the cup diameter the same basic way. That's how the jHorn does it. The instrument comes with a mouthpiece and three sizes of insert.

[tbonesullivan]

I've seen tuba mouthpieces that have spacers available to modify the cup depth. I think they are from Houser mouthpieces, and work with the Sellmansberger and Parker models.

I think it might be good for experimentation, but part of me really wants a more solid connection between the mouthpiece parts, and a cup/throat that really flow together well.

[JohnL]

Aside from other questions about this, wouldn't using an O-ring have been simpler?

An o-ring wouldn't give you smooth transitions. It looks like the spacer blends right into the cup and rim; no bumps or gaps.

[harrisonreed]

With this method you are slightly altering the entire length of the instrument. I'm sure it's not a big deal with a small spacer like that, but given a big enough difference it will affect intonation of the instrument but also the balance and intonation of the mouthpiece itself.

[stewbones43]

Stomvi have the "Combi-System" which has 1 mouthpiece "body", 1 rim, available in a variety of sizes, 2 shanks-large bore and small bore and 5 different depth cups.This means that you can vary the cup depth and shank to suit a variety of instruments and playing situations while keeping the same rim for everything.

The system seems expensive but you are effectively buying 10 different mouthpieces. (But then you will probably settle on one or two set ups)

Cheers

Stewbones43

[elmsandr]

With this method you are slightly altering the entire length of the instrument. I'm sure it's not a big deal with a small spacer like that, but given a big enough difference it will affect intonation of the instrument but also the balance and intonation of the mouthpiece itself.

I think the length aspect is insignificant, more significant is the shape. Not a lot of mouthpieces have a purely cylindrical section in the cup. I don’t make mouthpieces; but from talking to folks that do that shape can do a lot to the response. I would have to rely on some of our more expert crafters to say how much matters, but you do have folks like Monette out there saying that microns matter in this area.

Cheers,
Andy

[ghmerrill]

... folks like Monette out there saying that microns matter in this area.

What Monette says about this, and how they say it, seems a lot more like marketing than physics. They appear to offer no direct empirical evidence of these claims -- depending on claims about what "skilled players" can feel, "professional player feedback", and similar subjective (and subjectively phrased) evaluations. They then intersperse these kinds of claims with observations about how precise their machining is, and what they refer to as "acoustic reasoning" and their "reputation for perceptively superior performance", and throw in some broad and vague generalizations about "boundary behavior" and "impedance" (with no reference to any evidence or experimental results pertaining directly to their products).

That's all marketing and not science. It doesn't mean that they don't produce excellent products -- only that their marketing people have taken control of the descriptions of these.

[Doug Elliott]

Years ago I made rings to try that on my mouthpieces. I decided it didn't really work very well. Seems like it would work but it didn't.

[robcat2075]

I used a 3D printer to make a spacer ring to adjust the cup depth on a mouthpiece with a screw-rim.

You did that, but did it get you a difference of significance?