The audio quality in that tutorial movie is quite poor. I couldn't understand much of what was said. Also, I recommend keeping tutorials more focused and short. Tutorials that explaina single feature are great. Tutorials that walk through the creation of an entire composition need to be very well paced to hold the viewer's attention.
thank you for your feedback
audio quality can be improved and regarding the short tutorial actually number of users ask me to design complete tutorial so they can watch the whole composition because they were not interested in beginners tutorials.
i will design tutorials in different parts from now on which will be easy for users.
and finally it is difficult to design short tutorials if you are making tutorials on advance topics.