Sexis350

When reversing the car, when first driving it like in the morning when backing out of my garage I get a crunch noise when I go a depress the brakes (sounds like my brakes just took a bite of Dorritos). It sometimes happens while reversing or after I reverse then put it in D and drive a little bit and then brake. After that the brakes are normal again...

Didn't happened on OEM pads but I switched out the fronts with akebonos pads at 30k miles and I am starting to notice it more now at 36k miles. I read it might be shims or anti rattle clips. Any experiences or thoughts? When you reverse you use rear brakes or front brakes?