On Stack Height

Our rims use a 1/8" (3.2mm) stack height; similar to Houser's 0.135" (3.4mm) and a skosh more than either Moosewood, Giardinelli, or Osmun's stack height of 0.100" (2.54mm).

We use the higher stack height for one main reason; metal allergies.  Players on short stack rims very frequently contact the cup with their lips in our testing.  The higher stack height keeps you on the hypoallergenic Titanium rim and not touching the cup surface.  We do vary our stack a little by model, but it's to account for how the player's lips will interact with the rim; the X for example has you sitting much further in so we added .3mm of stack height to compensate.

But how much does a skosh or rim height matter? and is this something worthy of noting?

Let's analyze a simplified mouthpiece; our model has truly straight sizes (no s curves to be found here) and that makes the upper cup simply a cone.  That's easy enough to do math; 1/3 * π * radius ^ 2 * height.  Our extra stack E has volume π * radius ^ 2 * E when modeled as a simple cylinder.

Now, cup volume isn't everything, but it is one of the most important variables.  A higher volume cup will have narrower octaves and a darker sound, all other things equal.  The conversion of stack volume to conic volume of the cup is 3 * E (approximately, we're neglecting the tip of the cone, but close enough for this).  So for every mm of stack height we add, we're getting 3mm of cup depth worth of volume.

So back to the numbers; Houser has 0.2mm more stack height, so approximately 0.6mm extra depth to the cups.  With the somewhat brighter sound of stainless steel (vs the Titanium we use), that's probably a wash.

Osmun, Moosewood, & Giardinelli though are a different story; 0.66mm translates to 2mm of extra cup depth volumetrically.  The G and GM are only 3mm apart in depth for substantially different playing experiences so this is probably a noteworthy finding.  If you find your cup a bit bright on a low stack height rim, it's probably worth trying a higher stack rim, especially if that was the design intention of the cup.

We're pretty happy with how things play top to bottom and we're super happy to be part of an ecosystem that lets you mix and match a hundred years worth of rims and cups, so that's not changing.  However we may encourage you slightly more than we used to to move to our rims if you want the experience as-designed here.