Need help with powering a new system

[MATTBUT27]

I’m installing a new 2000 watt system which includes a 900 watt sub. I have the stock 132 amp alternator and the stock battery as well with no big three upgrade. I am wondering what I need to make sure I can power this system with no other problems throughout the rest of the car. Big three upgrade? New alternator? Another battery? 

[Joe X]

The power going to the sub or subs is usually 70% or more of the total power of a system so your numbers do not make sense to me.

 

Also bear in mind that the actual power a bass stage will take is about half of RMS when playing music or 450W playing at full power.

 

So the real power your system will take will be far below your estimate.

 

Assuming you have a 900W RMS amp for the sub and an amp for mids and highs I would just get a deep cycle battery, do the big 3 and have your electrical system checked to be in perfect condition, specially making sure your alternator is healthy. Nothing more to start.

 

You can always list your car model and all your audio system components models (amps, sub, etc.) for a more detailed power analysis.

 

 

 

 

Edited December 19, 2024 by Joe X

[BassMunky]

Big 3 help voltmeter just watch voltage

[MATTBUT27]

I’m installing a 2 channel to run two 6.5s (2x300rms) a four channel to run 2 3/4 mids and 2.5 inch tweets (4x50) and a five channel to run my sub, two more 6.5s and 6x9 coax’s for the rear stage (4x120 1x900) This will all be in a 2002 Dodge Dakota 4.7 liter v8

[Joe X]

Odd system, midbass centric it looks like, anyways here is a detailed power analysis, hopefully you can make your mind on what to do:

 

Assumptions:

 

Total nominal amp power(RMS) = 2180W, class AB = 1280W, class D = 900W

 

Usage: full power in all amps playing MUSIC ONLY.   Car services = all active (air conditioning, motor, lights, etc):

 

Battery Voltage = 13 V
Alt Capacity = 132 A
Usage Factor = 50 % (see above)

Total Input Power Services = 686.4 W
Total Input Current Services = 52.8 A

Total Input Power Audio = 1880 W
Total Input Current Audio = 144.615384615385 A

Total Required Power  = 2566.4 W
Total Required Current = 197.415384615385 A

Battery Current draw (A) = 65.4153846153846 A

 

So on these extreme conditions your battery will need to provide 65A to the system to keep your system playing at rated power.

 

At this point you have two options, play your system loud at times, not loud or off at other times to let your battery recharge. OR get an alternator that can supply those extra 65A or more and play loud all the time.

 

Most people do not play their systems at full power all the time and the battery usually has a chance to recharge and you don't need to upgrade your alternator.

 

To me my original advise stays, do the big 3 upgrade to a deep cycle battery and have your electrical thoroughly checked to make sure you have that current available.

 

As someone told you above it is a good practice to install a cheap voltmeter so that you know your average voltage stays the same as days pass and that you don't have voltage dips below 12.5V, if you have either you can think of upgrading battery and/or alternator.

 

[Jonathan Cole]

Upgrade to a high-output alternator and consider the Big Three upgrade for better electrical performance. Additional battery is optional but can help stabilize voltage.