Car Stereos: speakers and amps, dual voice coil, mosfet power supply

Question
QUESTION: Ok. I need help understanding how the whole thing works. I have am buying a Power Acoustik - 1200W Class AB Bridgeable 4-Channel MOSFET Amplifier with Variable Crossovers, 2 Alpine - 12" Dual-Voice-Coil 4-Ohm Subwoofer Handles up to 1500W peak power (500W RMS). I would like to get the maximum output and response out of these speakers would this be a good speaker/amp combo. And what is a variable crossover.

ANSWER: Hi,

I'd need more specs on the amp (specifically, how many channels and at what ohms) it can handle.

That said, the likely scenario is that the amp can do 2x(something)watts @ 2ohm bridged.

In that case, I'd suggest wiring each subwoofer's coils in parallel, and then wire the sub to each channel on the amplifier.

Variable crossover just means the amplifier can be set up to block out specific frequencies.  In this case, you'd want to have it block out anything over say, 125Hz since it's powering 12" subwoofers.

---------- FOLLOW-UP ----------

QUESTION: I changed the amp but the specs are Alpine - 1000W Class D Mono MOSFET Amplifier with Adjustable Crossover
◦1000W RMS (continuous) power x 1 @ 2 ohms, 14.4V, 20Hz - 20kHz, <1% THD
◦600W RMS (continuous) power x 1 @ 4 ohms, 14.4V, 20Hz - 20kHz, <1% THD
◦MOSFET power supply delivers clean power with minimal heat dispersion; thermal management control helps prevent overheating
◦Adjustable low-pass crossover
◦EQ and bass EQ controls for customizable audio; continuously adjustable gain control
◦Gold-plated RCA inputs; speaker level inputs
◦Top-mounted blue LED power/status indicator
◦STAR circuitry
◦Overcurrent protection
◦Signal-to-noise ratio: 100dBA
Spec for the subwoofers are(I want to hook up two)12"

Alpine - 12" Dual-Voice-Coil 4-Ohm Subwoofer ◦Handles up to 1500W peak power (500W RMS)
◦KEVLAR-reinforced pulp cone, oversized parabolic dustcap; HAMR surround and concealed mount gasket (KEVLAR is a registered trademark of DuPont)
◦High-strength brass voice-coil bobbin; 50mm voice-coil diameter
◦Dual progressive oversized Nomex spiders with integrated tinsel leads for added stability
◦Dual stacked magnets
◦Custom cast aluminum frame with integrated heat transfer plate; radial vented VC heat sink and airflow management system
◦11" top-mount diameter; 7-3/4" top-mount depth
◦Magnetically optimized motor structure
◦Frequency response: 25Hz - 500kHz
◦Sensitivity: 85dB
◦Impedance: 4 ohms

Answer
Your best bet in this case, then, is to wire the subwoofer coils in parallel, creating a 2ohm circuit, and then wire the two subwoofers in series, creating a 4ohm circuit, and putting them across the amp which will get you the 600W RMS @ 4ohms.

There's no way to get 2 ohms out of 4 4ohm coils.  Your options are 1 ohm, 4 ohms, and 16 ohms.

Justin