So, i have an old 2 way crossover (MTX RT0X01) and i want to power it up by using adaptor AC to DC, but i dont know how much ampere is needed... i only know its 12v, can i use adaptor 12v with 4A ? thank you
If the unit has a fuse at the power supply input that would tell you what the max it could ever draw would be.
Crossovers don't usually require much current so 4A is likely more than you need. 1-2A would probably be fine but having more current than needed is always OK just wasteful.