I just received my sette 270 grinder and was testing different setting for my espresso. I had to set at 2 in order for my 17g to be extracted at 24s (with 34g out).
Some additional info:
- im using LaSpaziale mini vivaldi ii
- beans are medium roasted at 6 days
- pressure at 7.5 bar (does this affect my extraction time?)
I saw many people only need the macro set between 6 to 10 to get the same results. How do I know if its a problem with my grinder, or something else?

I am very new to the coffee world any help is greatly appreciated!!

Comparing the numbers between grinders is virtually meaningless. There are simply too many variables for there to be any consistency. The proper way to calibrate an espresso grinder is to set it to its finest setting and pull a shot. If it chokes the machine, then it's fine. If not then an adjustment is needed, adding a shim in the case of a Sette. Once the machine is calibrated, then simply dial in to get what you want. On some grinders, especially flat burrs grinders, the recommended calibration is to set to burrs clash, then back off a bit. In either case, you need to be able to choke your machine at the finest setting.

As Nunas stated, add a shim if one isn't already installed. Its quite simple to do and only takes a few minutes. You'll likely see your macro setting jump up 5-7 settings. Right now I'm between macro 6-7 depending on the bean with one shim.

Thanks for everyone's advice! I will install a shim and see how it goes!!