Visually, you can check yourself to some extent. Just look in a mirror and see if the mouthpiece is in your mouth evenly.
You can also check out pictures/videos of great sax players to see how far their lip is rolled out, etc.
Your embouchure on sax will take some time to develop. You need to train and condition it. And then it will be stronger and work better.
As it develops, you should need to adjust it less. You shouldn’t be changing your embouchure all the time for different notes (high/low).
Here are a couple of questions from a beginning sax player about embouchure.
Hi Neal, I’m learning tenor sax since a few weeks. In lack of teacher (still searching), I use various books for instruction. Now I’m facing the first problem where I feel left alone: According textbooks, the embouchure should always stay the same. While playing low tones (lower C, D, E), I can produce a nice sound with decent tonging, but only for a very specific air speed/volume. Less air results in a delayed tone, more air produces the overtone for the fraction of a second. Hence, the only way I can vary the volume is to change my embouchure and air pressure at the same time. Am I doing something wrong?
Hey Marius, it takes time to develop control. Ideally you shouldn’t be changing your embouchure for different notes. Work on some long tones to develop the control, but realize that it won’t come immediately!
I was reading through the questions when I saw this, when I play my low notes I lower my jaw slightly and on my high notes my embouchure tightens gradually the higher I go.
Is that wrong?
It’s not uncommon to do that, but that doesn’t make it the best practice. And probably happens very slightly subconsciously. You want a pretty consistent embouchure throughout the range of the saxophone since it’s not practical to adjust your embouchure by moving your jaw if you need to do it quickly.