Generally as I recall, dbl reeds are easier to blow because it takes less air to make it work. Singles take more air and use more hand/finger control too. And being single take more air, they are generally louder. I'm no expert, but I'm a gooid meat caller when it comes to ducks.
Actually there is not a big difference between the 2, if you can do the basic calls on one, you should be able to do it also with the other. Maybe you need to change the volume of air you are using. Experiment a bit. Otherwise you could have bought a call that is not tuned right.
The Audacity of Bull Crap.
"Typical: Gun-loving, bitter bible-thumping white person" Barack Obama.
Hey I resemble that comment!!! Those are FIGHTING WORDS!!!