Trues about NCT and the microphone quality problem:
It can probably be fixed by connectiong of a mic to B input, however such a hardware fix should be supported by the firmware. No software fix alone is enough to solve the issue.
It's clear now that headset microphone has no physical connection to neither A nor B inputs and it can't be used to fix the problem. Maximum, that can be done without fixing the hardware side of the problem is software filtering of high frequency noises. It will probably make the voice recognition level slightly higher while on transport.
I'm using busses and subway in Saint-Petersburg, the trains are old and the noise level is extremely high so I have to unpair my dongle and call back every time, then pair it back. I had no possibility to return it and had to put up with the problem. My advice is to check if the microphone quality is good enough before buying.
Source: https://translate.google.com/translate?hl=&sl=ru&tl=en&u=https://4pda.ru/forum/index.php?s=&showtopic=927662&view=findpost&p=80261002&sandbox=1sebox @ 12/17/18 13:37 said:The fact is that csr8675 allows you to programmatically adjust the microphone gain. In the program for ES100, the microphone sensitivity setting is implemented. There it is used to mix sounds from the street to the music you are listening to. But in general, the microphone gain in our boxes is automatic (AGC) and the possibility to adjust the gain doesn't make much of a sense to me.
But noise cancellation in BTR3 (and not only) is more of a marketing trick, because at least two microphones are necessary for it to work. csr8675 chip can subtract the noise signal from the useful signal, if both of these signals are given to it from two microphones. But in case of BTR3 there is only one microphone hole.
I listen to the recording of my conversations on the street. When it is made simply from a smartphone, the absence of street noise is clearly audible, noise cancellation works. There are two microphones in my smart. In the recording of a conversation from BTR3, I clearly hear everything happening on the street, I can be heard loudly (because I’m talking in the hole) and all the traffic in the background, car signals and other sounds are heard quite strongly.
Here is the scheme csr8675 where you can see the connection of two microphones for the implementation of noise cancellation, there are two microphone inputs and two outputs of the AGC control signal (Bias).
It can probably be fixed by connectiong of a mic to B input, however such a hardware fix should be supported by the firmware. No software fix alone is enough to solve the issue.
It's clear now that headset microphone has no physical connection to neither A nor B inputs and it can't be used to fix the problem. Maximum, that can be done without fixing the hardware side of the problem is software filtering of high frequency noises. It will probably make the voice recognition level slightly higher while on transport.
I'm using busses and subway in Saint-Petersburg, the trains are old and the noise level is extremely high so I have to unpair my dongle and call back every time, then pair it back. I had no possibility to return it and had to put up with the problem. My advice is to check if the microphone quality is good enough before buying.
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