Car audio question about amps and speaker ohm rating

[J57ltr]

You could run each coil on a channel but what are you going to do about the component set?

Series wiring of subs increases it's impedance but parallel halves the impedance so 2 2 ohm coils in parallel would be 1 ohm and 2 2 ohm in series would be 4 ohms.

Jeff

[KaztheMinotaur]

Channels 1 and 2 would go to each voice coil on the sub. 3 and 4 would go to the component set.

I suppose I could bridge 1 and 2 and send them to parallel'd voice coils ?

[J57ltr]

No, If you parallel all VC's you will end up with a .5 ohm load across the briged output, the amp sees half of what it's presented so each side would see a .25 ohm load. You need to series each speaker then run them separately on the rear channels for a 4 ohm load on each side (and the amp will have better control over each speaker. If you run the pair in series again for an 8 ohm load and bridge the amp it will have the same power as single 4 ohm loads on each channel. You can’t parallel the speakers individually because you would have a 1 ohm load on each channel.

Jeff

[KaztheMinotaur]

On another related thought...

What are the amps wired with huge 8, 6, and 4 guage wire? Are those amps really pulling that much current?

Our high current RCs don't use that big of wire?

[J57ltr]

Use a minimum of 8 gauge. RC cars have very short wire. The longer the distance the larger gauge wire you have to use to handle the power. 8ga is good for about 10 feet and 50 amps continuous. Current draw is basically the RMS output of the amp (all channels) in watts then add about 60% more to that to account for the inefficiency of the amp (unless it’s a class D, then use 40%). So you have a 400 watt amp plus 240W for losses which is 640W of power required. I divide by 12V to end up with 53.3 amps at max power. Amps don’t put out their max power very often and you will probably see about a 15 amp average draw. Also make sure your ground is solid (and same gauge) on clean metal or you will have alternator whine. You didn’t say what the amp was but if it is a quality amp then this is about what you will see. I can tell by the wattage rating that’s not a real high quality amp, and is not 1 ohm stable, but use what you have I guess.

Jeff