Did the older BB's have the large 4" speaker? It's a 10 watt speaker.
I often experience some sound loss at 150+ yards in the wind. It seems the dogs can hear it, but it sometimes takes them a few seconds to pinpoint the location of the sound.
Couple of things here. What sound are you using? My experience indicates the "duck" sound is the loudest on my BB's. Also make sure you have the speaker pointed at the line, when training in the wind.
Finally, make sure the batteries are full charged. The sound does take a lot of battery power.