Have a customer who is replacing their old ATT 410 system with a new NEC system. Their current paging system is an ATT Powermate/Talkmate system (P/N's: 22050-001 and 22050-010) and has 4 PagePac horns (P/N: 22050-110). Customer says that on this system all 4 speakers are talkback and they they all operate in one zone. I am looking for recommendations on what to replace the paging unit with. Customer would like to be able to utilize the existing horns, but is not a requirement. But he would like to be able to have a paging system that will allow him to have 4 talkback horns all in one zone. I do not think that the current ATT paging system will work with the new NEC system so I am looking for suggestions on what to try. I talked to both Bogen and Valcom, and the products they recommend only allow 2 talkback speakers per zone. Ideas?