When I did my remodel I went with the Dixmor 2002 timers. I bought the 12v dc beepers for them. They are mounted in my coin box. They’re not very loud. I get a few complaints from people not being able to hear them. Especially if you’re washing with the high pressure spray when it starts beeping. Unless you’re standing in front of the coin box, you really can’t hear it. I used to use Ginsan timers and the gs-20 beepers were louder. Maybe because they were 24v. Is there a louder 12v dc beeper? Guess I could use a car horn!