Ah, Wilcox, mon ami, you have asked the big question! Am I CHEATING! Ha!
Honest answer. No, I don't think so.
In an effort to make better sense as a teacher, I make sure that I practice on about 10 differnet mouthpieces. Here's a list, from memory.
1.) Laskey 84C
2.) Laskey 81D
3.) Lakey 80*
4.) Lakey 40S*
5.) GR Skyrocket (a knock off of a Buddy Brisbois mpce)
6.) NYTC Stage 1
7.) Asymmetric Opera
8.) Asymetric 3C
9.)Asymmetric Lead
10.) Zotolla (I forgot the number), but it is similar in feel to a Purvaince 4*K4
I can play up to a double C on the 84 C. The 81 D is a little deep and I have a tougher time popping out the grand. On all of the others, I have essentially the same range I alwys do, just with varying degrees of brilliance to the tone and volume of sound.
I do this, in part, to minimize the "your cheating" syndrome!
I see it as I am just using the tool for the job! I'm OK either way. The other reason is that I don't see the asymmetric as something that reqires that I abandon conventionals. However, on the job, I use only asymmetrics. They work for me, and I like the endurance and freedom they give me.
As to my range, I've had decent range for some time. When I was on Maynard's band I used a Purvaince 4*K4. I sold it a long time ago. I wish I never had. It's a collectors item. Oh well... But I dsigress... When I was on Maynard's band I could hit some really nice high A's. B flats were a problem for me then. The B and Double C weren't bad either.
My intital efforts to build rage were based on the Claude Grond 52 week method and the Trumpet Yoga book. I'll disucss both later.
The PROBLEM, and thisis a BIG problem was two-fold. I used WAAAYYYY too much pressure. I was just mashing my chops - using brute force to get the notes. I was also using a bit of a stretch and pull. If you looked at my chops when i was playing a high A, it looked like I smelled something awful. The combination of misguided techniques gave rise to raging inconsistencies and often banged up chops.
All of my study for the past 15 years or so has not been to increase range. It has been to increase efficiency and freedom. This, I admit, will taint my point of view. For someone just starting out, the point of view could be utterly different.
I've have to run for now, but if this triggers more questions or ideas, keep posting! I relish the exhange!
Peace.
Nick