I have the D3300 and it's a great camera. I mostly use it for video and no complaints there. Video is always clear, crisp and looks great. My main issue is audio. I don't use the built in mic but instead use a matched pair of Sennheiser e614 condenser mics (phantom powered). These first go into a Behringer QX1202USB mixer and from there I have leads going out to the camera's external mic input.
The audio is recording pretty well however there is a very noticeable hiss which I cannot seem to get rid of.
At first I thought the mics were picking up room noise but everything in the room is turned off. Also comparing to recordings made with the mics going into the mixer and then out to a DAW instead of into the camera there is no background hiss on those.
So this leads me to believe there is something about the way the audio is being recorded into the camera. I have tried different mics but there is no change. I have also tried manually setting the mic sensitivity which helped a little but that hiss is still there.
I could of course go back to recording through the mixer straight into the DAW on the computer but it is so much more convenient to record the audio on the camera for when it comes time to edit the video.
I wondered if anyone here had any suggestions as I have run out of ideas?