need help on electrical info....(<<<first timer)

[dimhof 10+ year member]

this is my first time getting a stereo and i need help on how to install my system and what i need. i have two 12" rockford fosgate powers(1000 watts rms, 2000 watts peak), and two rockford fosgate 1000 watts rms amps. my head unit hasnt come in yet but it should be in today. i have heard some people say that i might need to put a battery in it or get a new alternator or something because of the large amount of watts running through it. i would be putting it in a 2000 jetta. both are capable to run at 2 ohms. i have heard many stories on what i would need to do. any help will be appreciated. thanks again.

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[iceteebone 5,000+ posts]

you will probably need a new alt. i use to have 1 rf 1001bd and my stock alt could barely keep up.

 

[dimhof 10+ year member]

Rockford Fosgate RFR3112-subs

Rockford Fosgate Power 1001BD-amps

 

[iceteebone 5,000+ posts]

i would recommend porting them subs around 33-35 hz. also use some 1 guage wire from the battery to the trunk. also are you strapping these amps together? if you are the lowest independence you can run is 4 ohms because each amp will see a 2 ohm load when strapped together and running 4 ohms but running both strapped at 2 ohms will give each amp a 1 ohm load and from expierience rf amps don't like that. what is the coil configuration of your subs?

 

[forbidden 10+ year member]

You can't make power unless you get power, so it is a very very good chance that a high output alternator and new battery system is in your future. After that issue is solved then you can attack the box and wiring problems or go for it now, there has been some great recommendations from iceteebone.

 

[ngsm13 5,000+ posts]

check out

http://www.excessiveamperage.com

http://www.mean-green.com

http://www.h-oalternators.com

all three...get quoted for a 200 amp alternator. it' will suit you well...also, upgrade stock battery to an optima red top. And upgrade big 3 to 1/0 awg wire (alt. to batt +, batt. ground to engine block, batt. ground to chassis) Also, never run system with engine off...if u want to even think about doing this even for a short amount of time...look into an optima yellow top as a second battery. good luck, peace

NG

 

[dimhof 10+ year member]

thanks for the help. they are four inch dual voice coils. is there anyway that the only thing i will have to do is get a capicitor or new battery? i really dont want to drop the dough for a new alternator. yes i was planning on running the amps seperately. what you said was like chinese to me. i understand the ohm thing somewhat but i thought since both the subs and amps were both able to run at two ohms that everything would be alright.

 

[forbidden 10+ year member]

Imagine your car trying to tow a super B train, this is what you are asking your alternator to do with the amps that you have. You need and must do the alternator upgrade to properly power your system. A high capacity battery is pretty much a must as well as a dual battery isolator and a second battery if you must. The big 3 is also a must do for you. A cap will have little impact on the system requirements as it is another device that the alternator must provide power to.

When you build your box, build it with two separate chambers, completely isolated from one another. This is a must when the amps are run separately (in most cases). You do not have the best match of subs to amps. The amps produce their full potential at 2 ohm mono, they are not stable to run continuously at 1 ohm mono. Your subs are dual 2 ohm coils, thus they can be parallel wired to 1 ohm or series wired to 4 ohm. As discussed above, 1 ohm is not an option, thus 4 ohm is the best configuration. The downfall here is that the amp will make only half of it's recommended power. Post up questions if you have them.

 

[dimhof 10+ year member]

i was planning on buying two seperate boxes. so you're saying that when i hook up my amps they will only put out 500 watts of rms instead of 1000? if i am correct then (i can still take them back) do you have any good suggestions on amps that run that high.

 

[forbidden 10+ year member]

Yes that is how the cookie crumbles. Are you after annoy the neighbourhood bass or decent respectable sound that can play over 140db (permanent hearing damage territory). This will determine whether you should use the amps, amp or what subs would be best suited for you. PS the box is extremely important, do not buy a prefab, have one built to suit the needs of the driver and the needs of the vehicle.

 

[dimhof 10+ year member]

i am after over kill if thats what you mean. where can you get custom boxes? if i hook up everything with the way it is two subs with 500 watts of rms it will still pound but its kind of wasting money because using half of the maximum output. how much $$ for the box also.

 

[forbidden 10+ year member]

The box will need to be built for you by a specialty car audio shop, not the big box guys. You have alot of options available to you for subs. If it was me in your shoes I would take either a do it right the first time approach or learn a little the first time approach. The second option will give you much valued tools to learn about how the system will work in your vehicle with your music. Which route do you think you want to take?

 

[dimhof 10+ year member]

another question...i have decided to ship the amps back and return them. after 500 watts rms its pretty much too much over kill (can that be?) anyways, i would like to be able to hear when i'm 40. i have decided to keep the 12" power subs. i have found two jbl amps that put out 600 watts rms at 4 ohms and are cheaper than the other ones so its a win-win. they are 1200 at 2 ohms though. finally what i wanted to know was that since my rms output will be drastically lowered will i need all of the alternator/capicitor/battery upgrades? thanks for all your help.

 

[forbidden 10+ year member]

Expect to here from the alternator gods quite soon, your electrical system will just no have enough left over to properly power those amps and big subs. I personally would have kept one amp and returned the other amp and the subs. I would have then used 2 good high output single 4 ohm coil subs and wired them in parallel to a 2 ohm mono load.

As I am a dealer I need to abide by the agreements set forth by this site. It is not in your best interest to purchase from me here in Canada for a multitude of reasons but I can point you in the right direction.

That said I would recommend highly two Eclipse aluminum 12" svc 4 ohm subs, model # SW9122. They work in a small sealed enclosure of 1.25 cu.f.t each and play to a nice SPL level and play deep with authority. Consider this and let me know.

 

[dimhof 10+ year member]

the alternator isnt a problem price wise, neither is the capicitor problem. i just looked at the manual for what was required with two of my amps and it looked like a road map. i am considering your proposal in depth. also when i wire them parallel that means i am running two subs off of one amp. thats possible with a one channel amp, right? so if i used the subs you suggested then it would just split the power in half. 500 watts rms for each sub?