I shoot a PSA takedown and a PTF one piece. I have been able to quiet the takedown a little more.
Longbows don't get the same amount of string slap on the limb tips that recurves do. I think this makes a considerable difference. However, a recurve can be toned down.
In my experience the brace height and arrow weight are major factors. One twist of the string can make a difference and I shoot 580gn arrows at 55#
I have also had some fast flight strings that I could not quiet down. Change the string and bingo, big difference. I can't say why it just seems to be the case.
I use felt pads on the limb tips to reduce the string slap. I use Black Widow spiders one third the distance from the tip and fur wraps at one quarter the distance from the tip.