Can I make the alarm louder?
If the VOLUME control is set at maximum and the alarm still needs to be louder, try various settings of the PITCH control. A different alarm pitch may be perceived as being "louder" because most people tend to hear different frequencies at differing volume levels.
Adding an external horn speaker may help in focusing the sound towards a particular location. With a REN of 1.9, adding a second Tone Ringer is not a viable option.
The Tone Ringer is designed for a relatively quiet environment such as a residence, an office or a small warehouse. Our Universal Alarm is more suited to a noisier (or larger) environment and replacing the Tone Ringer with a Universal Alarm will solve most "not loud enough" problems.
Our Extra Loud Bell or our Extension Bell may also both be worth trying because some people may be able to hear a "bell sound" better than they can hear an "alarm tone".