I've been playing tenor, alto and sop for years and got the bug to try to double on Bass Clarinet because I love the sound. Got a used Vito Resotone off of Ebay in February. A school horn but in fantastic shape....hardly used from the looks of it and/or the pads had all been replaced shortly before the school sold them all off through a wholesaler. Anyway, it's not the best BC I realize and the Clarion register is the hardest range naturally, first because it's hard to begin with, and second because it only has the one register mechanism. However I set myself to learning it and have gotten some mastery.
The first thing I did was get a better mpc than the Yamaha 4C that came with it. After reading up on them, and limited by my pensioner's budget, I got a used Vandoren B44 which thankfully does work much better for me. I have tried all sorts of reed strengths and types and find that a cane reed around a 3.5 or a 4 Plasticover work best. Right now I have a Francois Louis 3.5 on it and it sounds very nice and rich....when not sandbagging me with an errant squeak or the deadly goose call. Anything softer or harder and it squeaks a lot even when I have my embouchure right. I am playing tenor reeds simply because as a tenor player I have them already and BC reeds are not just more expensive but harder to come by. I mean if BC was as popular as tenor the damn things wouldn't cost as much as they do for a low C to begin with. Moreover they would have modernized the steampunk keywork and anti-ergonomic design of them a century ago like they did with saxes. However, they are what they are and at least they're not as much of a beast as an oboe or a bassoon. 😵😉
Okay, so my take on this wonderful sounding instrument is that for a long time sax-playing older person it is not an easy transition, but fun enough to play just for the simple joy of the sound I get just free improvising and noodling. I have no plans to ever play it in public because I am years away from that and will likely be dead before I have actually mastered it. So like most things in life in my supposed golden years, I take it for what it is on a daily basis. If the Pandemic ever leaves and I get the energy to play in jam sessions again, this will not be the instrument I take with me for sure. I play alto, tenor, and sop when not keen on beating myself with the black tube of death and they bring me back to that comforting sense of knowing what the hell I'm doing.
As you others know, the things that are hardest on the bass are that the embouchure and voicing are critical elements and the acoustical design of the thing makes it so that there is zero tolerance for any deviation from those being correct. It is not a tenor sax where you can get away with a too loose embouchure and sloppy fingering. And above all it does not take to honking like Yackety Sax. Blow too hard and it will let you know. Hit the wrong spatula key of the myriad that there are stuck all over it while fumbling to remember which one is which (my sax fingers want sax pinky keys damn them) and you get the Canada Goose of Death crapping on your birthday cake. That right there has no doubt been enough to make 75% of the students on this thing give up the ghost early on. But I am a glutton for punishment and I have to say that I can play the lower range of keys from low Eb to Bb with the register key and get the notes a 12th above most all the time now. So I am working on the air support and voicing of that to get it with the best tone possible. Sometimes however I find that I am suddenly up a third (?) from those notes (which are just like a sax....how comforting) and it throws me for a loop.
The other thing that takes practice and mastery, of course, is the proper use of the alternate pinky keys for E, F, F# in playing runs (walks are more like it in my case from Eb up to Bb up and down.....the E,F business is a bear to get down in my mind given the way those LH spatula keys are so awkwardly placed requiring you to alternate them with the RH ones. I mean you can only use the RH spatulas in one direction because the way they have one layer overlaying the other. I mean how dumb is that???Why they didn't make a flat table with rollers like on the sax is beyond me, especially since the same guy invented both instruments.
Anyway.....as I see it so far, the first key step to mastery, along with voicing and embouchure is finding the exact correct positioning of the clarinet in relation to your body. You need to find that so the mpc enters your mouth at the correct angle where you are blowing on the reed the proper way. Unlike a saxophone, which people can play lying down or holding over their head like Prez, the BC is requires decorum and proper positioning. I play sitting down because the weight isin't good for my neck or shoulders nor standing good for my knees and feet. I bought a nice height adjustable wheeled stool on Amazon that allows me to keep the peg at a fixed height and simply raise or lower the lever of the stool to get the correct position of the BC in relation to my body. Keeping a good posture is important too so as not to kill you spine or make you a hunchback and to keep your airstream hitting the reed correctly. The difficulty about this is remembering to maintain that position because unlike with the sax you can't gyrate around, grandstand, take a drink with one hand, or even turn your head while playing the BC.....at least not as a beginner anyway. Although a number of Jazz musicians have become famous playing this instrument, it is still a Classical Orchestral one and that means maintaining the physical decorum usually seen at Madame Tussauds wax museum. So with my Vito I angle the peg a bit underneath the seat so the less angled neck will be more vertical in my mouth. However given that as a sax player I naturally want to have it going in more straight I have had to learn to overcome that tendency because it doesn't work. Some BC have necks that have more of a vertical angle than this one, but in any case knowing how much to angle the clarinet is right away part of the learning experience. Then there is how much mpc to take in. Taking in more than with tenor seems to be the norm but taking in too much mpc is also not good. Finding the right amount takes time just as learning the correct amount and speed of air to push in. If you forget and pump it like a tenor in a rock jam you are going to scare the crap out of the neighbors or worse yet, your insignificant other. (If s/he hasn't already left you.)
So in summation, all in all it is a great fun instrument but not what I, as a saxophonist, might have imagined it to be to learn since the similarity between the two is more like that between an antelope and a giraffe than the impression the similar looking keywork leads one to believe.