Large Volume Difference Between Local Channels

Writing from Boca Raton, FL. There is a HUGE volume difference between the local stations on this system ... NBC affiliate WPTV requires cranking the volume up to almost "70" to hear, while a one station hop to CBS affiliate WPEC rattles the windows and requires turning volume down to "35" to be at same level as the prior station. The ABC and Fox affiliates are somewhere between those 2. 

I recently switched to Xfinity from YouTube TV and did not have this issue on their system.  Thoughts? Assistance?

Thank you!