How loud is the siren on a LYNX L5100 alarm system?

The Honeywell L5100 LYNX Touch is a self-contained alarm system and has a built in 85-110 dB siren. The siren is very loud and does not require any additional installation steps as it is built right into the control panel housing. The L5100 alarm control panel also comes with the siren turned on by default. The siren sounder level is selectable. From the L5100 programming mode, choose the 'Sounder' programming section and you can toggle the 'Burglary Alarm Sound' option to 'Yes' or 'No'. With the option set to 'Yes', you get the full 110 dB siren when an alarm occurs. With the option set to 'No', the siren is a higher pitched sound at the lower 85 dB level.

If you want to disable the L5100 siren, please check out the FAQ on turning off the L5100 siren.