Does the quality of the blowdryer make a difference in how much frizz you get when you're diffusing? Or is it more related to technique?

I've always gotten loads of flyaway frizz when I try to diffuse my hair... even if I wait until my hair is cupped before I turn it on, then keep it completely still, then turn it off and move it away. I have to wonder, is it my blow-dryer or something I'm doing wrong? I just have a $30 Conair blowdryer from the drugstore and I've had it for years.