Audio very badly stutters here under Firefox on a reasonable spec Win 8.1 PC - 3.6GHz i3-4160 dual core, GTX 970, 16GB RAM. Not an award winning spec system, but for single threaded maximised games (most) it's more than decent. ;)
Sound stutters on my PC which is pretty respectable. 16GB ram, Geforce 780 TI, i7-4790 3.6 GHz, Ubuntu.