mono or two channel are the best for subs but it depends on if your sub is dual voice coil or single voice coil, what ohm load the amp can handle, and if it is single voice coil and are using one sub you need to make sure you can bridge a 2-channel amp if that's the kind you chose... Next question you ask it may help to add a bit more detail. If I knew the sub brand and model, ohms, and if it's dual or single voice coil i could help answer that much better.
It seems like you're using a passive subwoofer. A passive subwoofer doesn't have a power source (an amplifier.) You will need an amplifier for your subwoofer. Let a professional set it up for you.
Yes, if it's a passive subwoofer, you might need to replace the amplifier for a new one as well. Too much or weak power outage is no good.
You need to specify if this is a stock or aftermarket subwoofer. You need to specify if this is a stock or aftermarket subwoofer.
Connect speaker cables to your receiver. Note that the subwoofer in this system is not powered, so you will need an amp that can power the subwoofer too.
depending on how many rms the sub is
You can get an 18" Pyle subwoofer but you will also need a large amp for it.
in fact , some subwoofer with amp. you don't need buy amp. give you one good guide http://www.12vcity.com
Should be between 200 -250 RMS Are you asking for the recommended POWER in watts RMS, or do you want to know how many speakers you will need? For a 5.1 speaker system, a system with 100-120 watts per channel RMS would suffice. This would be a total of 500 watts of power, plus the power amp that is built into the subwoofer. This would use 5 speakers, and one subwoofer.
Your computer doesn't need a subwoofer, but it would be nice to have one. If you want to get a sound system with a subwoofer, there are thousands of them on the market today, ranging from about $20 to several hundred dollars.
A Rockford 250 watt amp would compliment a 12" Subwoofer very nicely.
No, a preamp is not always necessary for subwoofer sound. You will, however, always need some form of "crossover" to ensure that you only send bass frequencies to your subwoofer.
To often mount a subwoofer you will need your desired subwoofer box of choice. Once you have decided what type of box you want, then you will need to take your subwoofer and insert it into the subwoofer hole. Then you screw it down. Once this is done you take your wires and run it into the subwoofer. An amplifier is not necessarily needed, but you'll definitely want one. You will then take your amplifier and connect it to your cars battery, and then also ground it to your car.