speaker question

Ive noticed when comparing my bct15x and BCD996P2, that the 15x model radio is louder than the 996p2 on the same frequency and volume level. Im not sure about digital, but its noticeable on analog frequencies, such as Noaa Weather Radio. Has anyone else noticed this, and shouldn't they both...

so here is my question can i have an individual frequency set to be muted until a 2 tone is received and decoded? or do i have to set an entire zone that way? i think i have figured it out thru trial and error but the way i have it, just doesnt seem right lol any help would be greatly...