WAY INOVERMYHEAD I HAVE ZERO EXPERIENCE SO PLEASE BARE WITH ME,I WOULD LIKE TO INSTALL A AMPLIFIED PA SYSTEM OR INTERCOM SPEAKER TO MY PHONE SYTEM I THINK THE CORRECT MODEL IS NEC DTERM 80.I HAVE A REPAIR SHOP THAT IS LOUD DURING WORK HOURS AND THE LITTLE SPEAKER IN THE PHONE IS NO USE FOR THE GUYS TO BE ABLE TO HEAR A PAGE.JUST ASKING SHOULD I JUST DO THE RADIO SHACK PA SET UP.I KNOW THE PHONE SYTEM I HAVE HAS A LOT MORE FEATURES THEN I WILL EVER NEED OR USE.