A golf club head with a channel sized to receive one or more adjustable weights and an external support structure that bridges, and thereby supports, the channel without unduly interfering with weight adjustment is disclosed herein. The support structure, which includes one or more stiffening members on the exterior of the golf club head, improves the sound quality of the golf club head, and is particularly useful to attenuate the lower frequency mode shapes associated with slider channel geometry in golf club heads.