Thumbs up [TIP] Low mobile reception and bad speech quality S4 Active

First Time I have to open a new thread

Is it possible, that the Data Connection speed has a negative impact on speech quality?

Today at home with WLAN ON and Mobile Data OFF,
I was wondering that I have only on telephone signal bar.

After making some changes to the mobile settings I came to the following conclusion.

The mobile signal strength is depending on your LTE/3G/GSM Settings whether you use your data connection or not!

LTE/WCDMA/GSM --> -101 dBm (1 signal Bar)
WCDMA/GSM --> -91 dBm (2 signal Bars)
Only GSM --> -69 dBm (4 signal bars)

Edit: A few minutes ago I met a friend and he was complaining about the bad speech quality of his new HTC one mini.
(He had the phone already replaced at his provider because he thought that the phone is defective)
After I changed his Data connection to Edge the speech quality was nearly perfect and his signal bar jumped from 1 to 5 bars.

I now it is not the best solution to reduce the Data speed you have paid for, but it definitely helps