Thanks Alex,
‘Having your timeline set to HDV is ok for now while most of your footage is HDV but when you do a final render you need to set the compression to something that isn’t going to degrade your images. Apple ProRes is your best bet – good quality/small(ish) file sizes’.
Would it be a good idea to change the render codec in user preferences > render control tab to pro res now?
I hadn’t changed the audio mixing setting but will do so now.
THANKS AGAIN!