An ar is a bit louder than an ak from my experience just due to the fact that the ar is a much higher pitched crack. But....technically both are in the 160 decibel range.Do you mean because of the sound? I sometimes bring my ar-15 and the 12 gauge was at a similar level. The ar-15 is so obnoxiously loud in there that I limit my shooting for everyone's sake but some of the pistols are also surprisingly loud as well.
AFS also added an ak-47 for rental which I'm interested in trying but I think would be even more obnoxious than the ar-15?
Why do you think an ak would be louder?