First, the 2 ch amp has to be bridgeable. In the "Pro Audio" world, PA, Sound System etc... some amps are easier to bridge then others. The easy amps are the one that have "Binding Post" for speaker output (the post you wrap wire around and screw it down or use banana plugs) to bridge these all you do is connect your speakers to both positive(+) post ( use both of the "red" post). This will add(bridge) the power from both sides of your amp and send it to your speakers. The subwoofers should be in parallel with each other,(the "in" from one speaker plugged into the "out" of the other). be aware that this will lower the speaker impedance making the amp able to send a higher wattage to the speakers.
Yes
If you amp is bridgeable you run + sub wire to ch 1 + then the -sub wire to the - of ch 2 of the amp. The same with the other sub + ch3 - ch4 that's how to bridge your amp.
yes all u have to do is bridge them together
Left positive to positive on speaker Right negative to negative on speaker
If you connect two 8 ohm speakers to the average car amp, then yes, probably. Most car amps can handle a 4 ohm load, which is what it would be.
Wire them in series and you should be ok.
First you will absolutely need an amp to power any subwoofers. Nowadays subwoofers come along with amp..& normally one 1200watt subwoofer decrease your car battery lifetime to 2-4 month
yes, you can, either via a Y-cable to the sub output, or via a pre-amp, or hook them up parallel to a mono amp or if you have a 2 channel amp then just hook them up regurally but if you have a mono amp then...have two positive and two negative wires coming out of the amp then hook 1 negative wire up to the negative spot on a speaker..then do the same with the other..then do the same with the positive
3 passive sub at 8 ohm imp in parralel will be 2.6+ impedence.Most of the professional sum amp can take up to 2 ohms load per channel(check the spec of the Amp)eg: you should be able to connect max 4 subs in each channel(match the watts pwr to amp)
You won't notice any stereo separation with two subwoofers because our ears perceive bass as omnidirectional. Two subs can make more volume than one of the same size. If you are using two subs, you should either use two separate mono amps, or a two channel setup. As long as the amps have a high pass filter they will work equally well, although the wiring will be simpler for the two Chanel setup.
You could with a 4 channel amp. Bridge it to two channels and hook up the two 8 ohm woofers in parallel on the one bridged channel. Then hook the two coils on the dual coil woofer in series with the other bridged channel on the amp.
Yes you can depending on the wattage of the amp. i personally would only put two 12's on one amp. cause it will still bump hard!!(: