I need to know if I need a high output alternator

Hey mate.

Most car stock system will handle up to 1000rms and anything more than that, modifications / additions has to be done to accommodate the electrical demands from your big power amplifiers. 

In your scenario, you will need to;

• upgrade your alternator;
  
• do the big three;
  
• upgrade to O gauge power/ground wires, ( which you may already have)
  
• add secondary battery to meet your current amperage demands;( would have to be Optima or any high performance battery will high CCA) dry cell, marine) etc..
  
• if you are unsure, visit a car audio shop and show them your current setup so, they may be able to steer you which additional gear you need/ and need to add on;
  
• Avoid running your current system as it poses a risk to your cars electrical system and to you and your passengers. 
  

There is a reason why your amps turns into a barbecue hotplate, its because it lacks the reserve current it needs to run the amp efficiently.  Personally, I would not be using your sound system until you get this sorted out as continued usage could cost you more 'dosh' in the long run so do yourself a favour and either;

• stop using your sound system;
  
• take the big amp out and run a smaller one say, 1000 rms monoblock until you get the upgrades done;
  

Since you are using big power, then you have to supply the current demands to your system, and theres no short cut around it.  Not doing so will induce a risk factor to your rides electrical system not to mention in worst case scenario, your vehicle could catch fire :uhoh:

Better to be safe then sorry in this case! :graduate:

Let us know how you go mate!