Tires: low tone wabble noise 20mph and up changes with speed, lexus is 350, soft tires

Question
I have a lexus IS-350 with 7k original tires -bridgestones. These tires in front cannot be rotated due to different size than the rears. Car comes with disclaimer of 15,000 need replacement on tires due to obvious soft tires. Lexus says there is mainly on the outside of the tires at each tire notch it is higher in the front than the rest of the notch. This is on the action side of the tread. They used the word clipping. Recommended replacement of tires , balancing,allignment. what causes this clipping? This noise increases in speed as the car goes faster. sounds like a wabble but low pitched. heard by tech. treadwear wear is even. what would you do if you replace tires and aligned still noise?

Answer
Ralph,

You have an alignment problem that is causing irregular wear.  You are in the very early stages of it and the wear is only noticeable by the noise.

Alogning the vehicle should help eliminate the source of the noise, but only time is going to wear a new pattern in the tires - unless you replace them.