Thanks for the replies. I did think about the IP phone speaker hak, but I think that would be the last resort.

The main site is a typical 600 ohm paging output from an esi cs200 phone system. I need to make the remote warehouse part of the all call over head paging. I have two remote IP phones at the remote site in the offices but need to announce in the warehouse also. A Valcom VIP810 at the main site and a Valcom VIP800 at the remote site with a 1030C paging horn would do the job perfectly, it's just very pricey for a single paging horn. I was hoping someone may have used some other system that is reliable and more cost friendly.