I installed Avid SD7 V-brakes on my Cross check, replacing Shimano BR-R550 Cantis in an effort to stop the canti's incessant squealing. Didn't help. Fitted Koolstop Salmon pads. Didn't help. Toed the pads in some, then a lot, then flat. Didn't help.

What finally stopped almost all of the noise (not quite all but close) was substituting Koolstop's Dura Type road brake holders and Salmon road pad inserts for the MTB-type holders and pads. These shorter holders and pads must be more rigid and have finally quieted the bike down.