Impedance matching

[bob golding]

hi i am designing a small PA system using active speakers. i am planning to use 2 4 ohm exciters per speaker with one exciter connected to each channel of a class d amp. as i am splitting the input between 2 separate amps anyone know what effect this will have on the input input impedance of the amps and how to compensate for any mismatch?

 

[Sergeauckland]

The two amplifiers will presumably have their inputs in parallel, so the input impedance as seen by the source driving the amps will be halved. So, if each Class D amplifier has an input impedance of 10k, say, the source will be driving 5k.
In practice, that will be fine, as any decent source will drive 5k perfectly well.

S