Proton dynamics in NH+-N hydrogen bonds is characterized by high-pressure dielectric and calorimetric studies of ferroelectric/paraelectric phase transitions in perchlorate and tetrafluoroborate mono-salts of 1,4-diazabicyclo[2.2.2]octane (DABCO), [C6H13N2](+). ClO4- and [C6H13N2](+). BF4-. The p-T phase diagrams of these ferroelectrics have been determined and described. The positive pressure dependences of T-c testify to the strong coupling of the ionic dynamics with the proton disordering in the NH+-N hydrogen bonds. Close isostructurality of the crystals provides a unique opportunity for analysing the proton disordering at varied crystal environments.