I bought a muffler for the Ridgid shop vac today at HD. Paid $12 plus but could not hear any difference in the noise level with or without it. So I measured the sound power level at 3 feet; 83 db without and 82 dB with. Don't buy one, save your money. I was surprised at the 83 dB number. Many of my tools are louder than that.
bababrown
bababrown