On Materials

Here at Strachan Brass, we're all about fundamental research (when we have time).  We're finally in a place where our in-house production is stable, our drawers are stocked with cups (mostly) and we're not totally on fire with rims.

Anyway, I had a Ti CV on hand, my prototype Model One, and of course, many brass ones.  I'd had a stick of Alu Bronze staring at me for a while and decided to go ahead and make up the Bronze CV to complete the set.

Setup: All cups are model CVs played in the same Yamaha 863 at C4 (C in the staff) on the Bb side of the instrument.  I held each note for 10s just to even out any fluctuations.  There's a bit of background noise in our shop because we live on a train line, etc., but the spectrographs are pretty clean, so we'll roll with it.  All were recorded on a Blue Yeti Mini (what was handy on the desk at the time) within about a minute total of eachother.

The detachable rim cups were played with my standard Titanium rim (an RS18), and the brass one-piece has an integral brass rim of approximately the same dimensions (it's an RS17.75, but close enough).  The model one is also gold-plated for whatever that may be worth.

I ran each audio sample through a spectrograph generator so we can take a look below.  I've also included the raw audio, which is quite boring to listen to.

The cups (with rims) had the following weights:

Model One: 34.4g

Brass CV (w/ Ti rim): 31.5g

Bronze CV (w/ Ti rim): 28.2g - Aluminum bronze is lighter than brass

Titanium CV (w/ Ti Rim): 19.6g

Qualitative Findings:

First off, listening to the recordings, only the bronze piece stands out; it's clearly darker, and that shows in the spectrogram, with far fewer visible bands (by my count, probably 7-8 fewer harmonics at the upper end of the spectrum).  The Titanium is surprisingly brass-like; if anything, it's slightly darker than brass though the differences are hard to both see and hear in such a short sample.  What's interesting is that to the player, the Ti feels quite different because it's giving you a bit different feedback at the rim - that's partly due to the metal's properties, but mostly it's that the all-Ti setup is more than 10g lighter.

Overall, the differences here are fairly slight; the Ti is a little darker than brass and has a more ringing sound to the lower overtones.  This is much less of a difference than a steel cup from brass (and in the opposite direction!).  The difference in the different cup geometries would overwhelm this small difference in materials.

The great news from this is that if you have a brass rim, switching to a Titanium one should make very little difference in your sound production, though it may feel a bit different to play (again, because of the mass differences).  Similarly, a full-Ti cup will darken the sound slightly, but not excessively.  In our opinion, factors like allergies and desired feel should be a more significant factor in choosing than this relatively small sound difference.

Bronze is interesting.  Despite being a lighter material, it plays as though it's much heavier than it is.  The sound is smoother and significantly darker.  This would make a very interesting material choice to allow you to run a tighter slotting brighter cup in a setting that might not otherwise be conducive (a G or GA in bronze, for example, could prove very useful to a player who finds those too bright).  On this particular horn, the Bronze CV is actually quite a good option since it tends to be quite bright in practice.

Results:

(Folder: Mouthpiece Material Comparison)

Brass CV (w/ Ti rim)

Bronze CV (w/ Ti rim)

Ti CV (w/ Ti rim)

Model One