recombine iMovie clips from miniDV without volume problems between them?
This could have two reasons:


Transition between clips 

 If you can see that symbol between your clips you have a transition between the individual clips. Delete the transition and the audio blending is gone.
Audio blending 


If you see these inverted parabola arms on the audio it means you have an audio fade out and fade in. Drag from the end of each fade to the beginning/end to your clip and it should be gone.