Adding a resistor in a parallel wiring system

Doing that won't affect the damping factor of the other three drivers. But perhaps you don't even have to add the resistor. Three nominally 8 ohm drivers in parallel with a nominally 4 ohm driver results in a nominal overall impedance of about 1.6 ohms. If you step that up 4x with the Zero, and probably also 3x or possibly even 2x, your amp should be happy (in terms of the load impedance it sees; I'm assuming the amp can supply sufficient power for your application).

Keep in mind, though, that without the resistor the 4 ohm driver would receive twice as much power as each of the others, while with a 4 ohm resistor the 4 ohm driver would receive half as much power as each of the others.

Regards,
-- Al

Hi Al,

Thanks for the response. Now I'm thinking, since the zero has several input wires, maybe I could use the 3X wire on the three 8 ohm drive and then connect the 4 ohm drive by itself on the 2x wire. That way all of them will practically be 8 ohm. Would that work or will that just burn the amp? Thanks.

Thanks,
Ryan.

As I interpret the information provided at zeroimpedance.com, if the Zero is being used to increase the load impedance seen by the amplifier (as opposed to decreasing it) there is one and only one pair of output wires on the Zero that can be connected to the speaker drivers. The choice of 2x, 3x, or 4x impedance multiplication is made based on which pair of input wires on the Zero is connected to the amplifier. So it appears that you would not be able to connect the 4 ohm driver (plus any resistor you may place in series with it) to the Zero any differently than the 8 ohm drivers.

Regards,
-- Al

I see, I wonder whether it can be wired backwards. I'll test them tomorrow when I get them thanks

No, you definitely don't want to wire them backwards. That will LOWER the impedance seen by the amp, by 2x or 3x or 4x depending on the connections. So the 1.6 ohm combination of the four drivers would be seen by the amp as well under an ohm. See this paragraph in their FAQ.

Good luck. Regards,
-- Al