I have this camera and find the audio much better than my other cameras with audio.
Two many unknowns to troubleshoot, but I will give you a few places to start.
Disable Noise filter in the camera.
How is this connected to your network - are you watching through the DMSS app, web browser, NVR, etc. Is the camera connected to your router? These things all affect the ability to transmit the huge data needs of these cameras.
Unlike the Reolink that you saw the video is poor (and thus the poorer quality video means not as much data is being used so then the sound quality can be better) as the consumer stuff like reos and Ring prioritize audio over video, a Dahua will prioritize video over audio IF there is an issue with one's system that prevents it from passing the full bandwidth.
The next item is the camera itself and settings:
Keep in mind that these type of cameras, although are spec'd and capable of these various parameters, real world testing by many of us shows if you try to run these units at higher FPS and higher bitrates than needed that you will max out the CPU in the unit and then it bugs out just long enough that you miss something or video is choppy. My car is rated for 6,000RPM redline, but I am not gonna run it in 3rd gear on the highway at 6,000RPM...same with these types of units - gotta keep them under rated capacity. Some may do better than others, but trying to use the rated "spec" of every option available is usually not going to work well, either with a car or a camera or NVR.
Look at all the threads where people came here with a jitter in the video or IVS missing motion or the SD card doesn't overwrite and they were running 30FPS and when people tell them to drop the FPS and they dropped the FPS to 15FPS the camera became stable and they could actual freeze frame the image to get a clean capture. The goal of these cameras are to capture a perp, not capture smooth motion. When we see the news, are they showing the video or a freeze frame screen shot? Nobody cares if it isn't butter smooth...getting the features to make an ID is the important factor. As always, YMMV...
Further, these types of cameras are not GoPro or Hollywood type cameras that offer slow-mo capabilities and other features. They "offer" 30FPS and 60FPS to appease the general public that thinks that is what they need, but you will not find many of us here running more than 15 FPS; and movies are shot at 24 FPS, so anything above that is a waste of storage space for what these cameras are used for. If 24 FPS works for the big screen, I think 15 FPS is more than enough for phones and tablets and most monitors LOL. Many of my cameras are running at 12FPS.
In fact, many times if a CPU is maxing out, it will adhere to the FPS but then slow the shutter down to try to not max the CPU, which then produces a smooth blurry image..that is the video my neighbor gets who insists on running 60FPS. He gets smooth walking people but you can't freeze frame it cause every frame is a blur, meanwhile my 12FPS gets the clean freeze frame. Shutter speed is more important the FPS. We both run the same shutter speed by the way, but his camera CPU is maxing out and something gotta give when you push it that hard.
So to see if it is a trouble with your networking chain, go in and try the following:
H264
no smart codec
1080P resolution
1000 Bitrate
CBR
10 FPS
10 iframe
Noise filter off
See if that allows the audio to be nonchoppy. Video will probably be crap though. If it works then, then you know it is an issue somewhere along the chain and/or you were pushing the camera too hard.
