The case itself makes no noise, it can't be loud. lol. The fans inside are what's making your noise. Case fans, cpu fan, gpu fan all make noise. Good fans, good cooling, good ventilation will all help lower noise. Good fan profiles as well for fan speeds can affect this as well. I just build a new pc and have 6 fans plus 2 gpu fans, so 8 total, and it's dead quiet, mostly to creating a good fan profile to control the fans. "Turbo" mode on my fans sounds louds and keeps my temps at like 49c. A quiet profile keeps the temp at like 51 and is silent. For 2 degrees, I'll take the silence.
Granted a good case will help, but you need to look at your cooling system over anything for noise.