D5300 & D5100 sound different in video

Independent filmmaker using D5100 to film. Purchased D5300 as upgrade/2nd camera for multiple angles at same time. Purchased identical external mic we have for D5100. The sound quality between the two cameras was completely incompatible. Couldn't use footage from one due to the drastic difference.
Is there a way to change settings in camera to make more compatible? Please help.....

I can't help you on this Renee, but I do want to say Welcome to the forum. Someone will probably come along soon to address your question.

After thinking about this, a possible and probably better solution might be to use a totally separate recording device fed by the multiple mikes required for the audio. Then combine it later with the video. I don't do videos usually, but that having worked a little around audio systems, that would be better than using the two cameras for audio

I started off in TV many years ago and many times we would go on location with multiple cameras to record something and for the final edited video we would record the entire (Lets say song) on each camera. Then in editing we would decide which other camera we wanted to cut in a shot from and then edit one the video syncing the audio from shot one with the video from two. I edit video to music even now on my computer for my Drone video. Your audio will sound much better if it does not change sources in the middle of a scene

Renee...

You know the D5300 has a stereo microphone, and the D5100 doesn't, right? There will be significant differences between the audio between those two cameras.

Hello and welcome........................Unusual problem and although I have owned both cameras over the years I only ever used them for still photography.