Shellac for reflectors or resonators?

The surface of the 'resonator' is going to be reflective- but from the standpoint of wavelength,
even the largest keys on a bari are sitting at about 5khz, so they are going to have limited
effect on the spectral content of what's coming out of the body or the bell.
I quite agree that sound waves don't reflect on the walls, "resonators" etc. They're far to long.
However, if you think about things at the right scale - it's statistical mechanics. The wave along the instrument describes the (offset from atmospheric) pressure, pressure is "average" kinetic energy and energy clusters around the resonances (tone and overtones). But that's only stable so far as the walls are ideal - perfectly elastic. If molecules lose energy when colliding with the wall, they'll lower the pressure a bit, effectively contributing to other partial frequencies.
If you fall for that story, pads are - compared to brass - much less reflective for air molecules so you should get more energy spreading out to partials and higher overtones. Putting reflectors over pads should reduce the amount of energy leaving the fundamental and lower overtones.
 
I quite agree that sound waves don't reflect on the walls, "resonators" etc. They're far to long.
However, if you think about things at the right scale - it's statistical mechanics. The wave along the instrument describes the (offset from atmospheric) pressure, pressure is "average" kinetic energy and energy clusters around the resonances (tone and overtones). But that's only stable so far as the walls are ideal - perfectly elastic. If molecules lose energy when colliding with the wall, they'll lower the pressure a bit, effectively contributing to other partial frequencies.
If you fall for that story, pads are - compared to brass - much less reflective for air molecules so you should get more energy spreading out to partials and higher overtones. Putting reflectors over pads should reduce the amount of energy leaving the fundamental and lower overtones.
When you are in a concrete room there are more higher partials in the sound than in a teak wiooden chamber.
The elasticity of brass is comparable with teak. The elasticity of most metal reflectors is comparable to concrete, The elasticity of plastic reflexctors is comparable to hard wood and brass.
They couldn't measure a difference in sound between plastic and metal reflectors. When the reflectors cover approximately 15% of the surface and the effect of the difference in elasticity is not measurable it is unlikely that the elasticity of the remaining 5% surface (app.) in leather has a measurable effect on the sound.
 
Its worth fixing because it sounds lovely after a bit of twiddling and cleaning, apart from having to press hard because of the pads. Ive had 3 directors and one 10m in the past and this badly made mexicon made by jose blindairos and his lump hammer sounds the best out if the lot.
If this one sounds the best. Study every bit of how it’s assembled. Duplicate exactly how the pads are installed. Order samples of pads from each pad maker. Test to compare samples to orginals.
Music Medic will made custom pads to your specifications.

All your questions are answered. The answers are right in front of you.
 
When you are in a concrete room there are more higher partials in the sound than in a teak wiooden chamber.
Just to add.
What I observed was that within a sax, talking about sound waves reflecting off of pads / resonators is not good physics.... The "wave" of a standing wave is a longitudinal pressure profile, pressure is "average" kinetic energy etc.

... Within a room that's probably several times the length of the sound waves - you can properly talk about the waves reflecting off of the walls and consider if the material might absorb, scatter or reflect waves of various frequencies etc.
 
Im going to ring up selmer and ask them, matt stroher says he disagrees with them using less shellac and recommends a credit card thickness, I just want to get it right. Shallow conn cups 1970 same stencil and tone hole size as 10m. You know one of those rubbish mexicons that sounds the same but without the crappy wire key guards.
Why call Selmer ? Conn Selmer USA ? Dunno if they have any technical support. Maybe a generic installation sheet. Like “ use a quality pad with sufficient adhesive to hold in place”. No company will offer instructions these days. Verbal or written. Liability of product damage or personal injury had eliminated factory support.

From your comments I assume that you have a Conn 16m Director tenor from 1962 to 1970? Made at the Nolgales Mexico factory.
Here below is a set of original pads removed from an 16m. The pad on left excluded.
1735840471293.webp


How much shellac I apply is determined during dry fitting. Conn key cups have a dome shape. The volume needed is a craftsman’s judgment call.
To quote Matt Sthorer “ I have seen pad work done in ways I cannot duplicate “.
So do your due diligence. Observe what you desire to duplicate and execute your craft knowledge.

1735841520833.webp
 
Im going to ring up selmer and ask them, matt stroher says he disagrees with them using less shellac and recommends a credit card thickness, I just want to get it right. Shallow conn cups 1970 same stencil and tone hole size as 10m. You know one of those rubbish mexicons that sounds the same but without the crappy wire key guards.
Go with Matt's advice.
Manufacturers often skimp on shellac/hot melt glue because of the processes they use to seat the pads. There's little, if any, fine adjustment involved - which is why the advice to have a horn checked out by a skilled repairer even when new still stands today.

To give you a pertinent example...
Few manufacturers produce horns with truly level toneholes, which means the pads have to take up the anomalies. When they're new - and thus supple - they can usually accommodate the defects, but as they age they stiffen up and will need adjusting. It doesn't take long. So you heat the key cup up, draw a section of the pad down to take up the leak and call it done. But if there's no or insufficient glue behind the pad you've effectively drawn the pad into thin air...with just perhaps a thin smear of glue holding it in place. It's just not going to last.
With sufficient glue you can draw the pad down and the molten glue will flow into the gap and hold it securely in place.

I work on horns pretty much every day where the major cause of unreliability is poor pad seating due to lack of glue. It's annoying...but it pays the bills.
 

Similar threads... or are they? Maybe not but they could be worth reading anyway 😀

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