I didn't get a photo in the end but can confirm you're right. All works by wiring the SPK port on the twin alert to the right-hand extension speaker outlet on the panel. The twin alert has its own volume control pot.
Thanks for your help.
I hoped you would reply. Thanks very much @GalaxyGuy. I had already tried connecting the speaker to one of the Dimension outputs and then programmed 99 output as E/E Horn. (Reason for the speaker is because we can't hear the keypad beeps outside.)
I'll give this a go again later and see if I...
My first time using a Pyronix Twin Alert with a Dimension panel.
I was hoping to use the device both as an internal speaker and sounder. Sounder works fine connected to bell output, but I don't understand the mode of operation of the external loudspeaker port on the Dimension panel and how this...