I just know that because there are some stadiums that do not have enough supporters, but the cheers sound already full lively with drum strings also.
what do you think?, is real or use recording through speakers
I have been to the local and national stadium in my country and what I'll tell you is that the chants are real. If it is a "hot" match the pressure can be felt all over from the die hard fans. It's even more powerful when they start singing in solidarity. And when the crowd go wild when a goal is scored, you would literally fill the vibrations of the pillars.
It is definitely real especially when the games are on tight and exciting part. I've been in multiple local and national sports and esports events and the crowd can be too loud particularly when the chant and cheers starts. Everyone will join and even the opposing supporters will also starts chanting as well. However, when being televised, there are certain background noise and cheer being added on which can be easily identified, it's not too loud compared to what's already happening on the stadium but it's noticeable.