Almost all my spinning combos have the line slapping in the first rod guide, which I feel while working a life and retrieving. Are all manufacturers switching to smaller first guides? It’s really annoying. 

one reason for this is almost universal switch to braid for spinning tackle.  

(the other reason is keeping rod weight down)

Takes the stiffness of mono/fluoro to produce line slap.  

 

 

my kingfish rod has big guides

My experience has been anything larger then about 8# to 10# fluoro on medium spinning rod with a 2500 sized reel gets terrible line slap. Mono isn't quite as stiff. Or the Berkley XL that use anyways. Like Bulldog said the line is just too stiff and you get big loops coming off of the spool that slap against the rod.

FM

What line are you using? I use sufix Elite and Siege mono on my spinning rods and I'm not getting that occuring?

You mean slapping the blank between the reel and first guide?  If so, try smaller arbor reels, softer line and KVD line n lure conditioner.  You could look for rods whith the first guide a little further out too

19 minutes ago, Delaware Valley Tackle said:

KVD line n lure

^^^Be like Mike^^^

Love this stuff.