Wow, this has to be the loudest and best solution for you doozers.
Ever sleep-in because your alarm clock wasn’t loud enough? With this design that is guaranteed not to happen! This hack takes a standard cheap alarm clock, some interface components and a fire alarm bell to get the job done right. Normally these small alarm clocks use a piezo buzzer to attempt to wake you up. The alarm signal is hijacked from the clock circuit board and used as an input to the interface board