Wiring 2 4-Ohm DVC Subs Going Crazy

"Running 8 ohm" will require less amplifier power than lower impedance loads so it will place less of a strain on a vehicle electrical system.  Your friends who are adding water to their batteries either need new batteries or better charging systems in their vehicles, it has nothing to do with an 8-ohm speaker load.  There is a long sticky thread about using one VC on a DVC speaker that you should read, but in general you need to de-rate the power handling to about 75%; meaning if your DVC speaker is rated at "200 watts" you need to use no more than 150 watts to one VC.

Well I went out and bought 2 800 watt mono block Pioneer amps.  They run at 2 ohms stable, so they work perfectly for pushing out the power I need for the 2 alpine type-r 12s.  I am supposed to be getting 380 watts to each sub.  With the subs rated at 500 watts rms, it should be safe for both my amplifiers and subs to run them the way I have them set up now.

Only problem now is that I am drawing way too much amperage from my amplifier, and they subs cut out after about a minute of loud playing.  They will cut out, then come back, then go back out, waiting on more power from the alternator in battery is what I am assuming.

The Pioneer 7200M amplifier has 2 30A fuses on it.  But the specifications sheet says it pulls 33A at continuous power at 4ohms.  16A current draw for mono at 2ohms.  Is there a difference between the current draw and current consumption?  And which number should I use when choosing a HO alternator?  If both amps are taking 33A each, then the 66A total from both amps and around 15A for my head unit, then Im adding about 80A of pull from my alternator and the factory electrical system.  Should I just buy a HO alternator that is rated at least 80A higher than my factory 80A alternator?  I have commited to a 130A alternator on ebay, but have not heard back from the seller, so I may have to cancel that alternator and buy another one.  Do you think a 130A alternator will be able to handle the draw and give me full power from both amps onto my subs, or should I tell the guy I dont want the 130 and get something larger?

Thank you for all of your comments so far, they have helped me build a larger and better sounding stereo system, I am almost done, just trying to put on the finishing touches now.

Don't go with an alternator yet. Read the sticky regarding upgrading the "Big 3". Start there before doing anything else. It's the cheapest and easiest way to make sure you are getting the most from your charging system. Even if you beef up the alternator, the "Big 3" are going to be what is limiting the supply of power to your amps and back to your battery. Once you do that upgrade, if you are still having problems, the discussion can resume regaring an upgraded alternator. You can simply throw money at the problem, but if you do so with some direction, you can get the most bang for your buck.

That would be my opinion.

That's a gain level adjustment.  They are not waiting for more power from the car's source when they cut out.  You need to set the amp gains correctly.

once you set your gains properly--check your voltage right at the amp

while you have them playing.  most new amps out there wont actually shut

down until your below 11 volts.  I have never seen a need for an electrical system

upgrade- running just 2 small class D amps.. and come to think of it --check the impedence of your

subs wired up--with a dmm--to make sure you have a 2ohm load and are in fact wired up

correct.

g/l