200 amp alternator idle low amp output

[Jayraza]

Hello everyone I’m new here, forgive me if this is not the right section. 
 

I had a shop completely replace the alternator and battery with a new one and supposedly amped this one to a max output of 200amps. I got my car back and the voltage holds steady at 14.2 with many stock components on. 

 

however when I play my system (skar audio 1500rms, 2 skar12’s at 2 ohms) my voltage drops as low as 13.0 at the lowest drops, when the big drops are over it immediately goes back up to 14.2. seems to draw 20-30amps turned up. 
 

using an amp clamp meter I measured the current from the alternator post at idle at 20amps. With everything on (a/c lights etc)including the system playing loud I got readings up to 80amps. Without the system playing readings were 50-60amps.
 

Is this normal for the kind of alternator I have? Or should a 200amp alternator be capable of maintaining voltage during the system playing with car running? Should my idle voltage be higher or is that more related to the rpm of the pulley?  Btw, I never received any bench test certificate, I picked my car up after hours.

 

edit: I will be adding a secondary battery just for the audio system soon. 

[Mike4068]

Everything is normal. If you want to stay higher then you need more reserve in the form of a higher ah battery. Ain't nothing wrong with 13v though. Was that at idle or at 2k rpm? 2k is when the alt is going to be able to make it's power. 

[Jayraza]

At idle 13v and I measured 13.2v at 2500rpm but it was staying mostly at 14 volts during system play. 13.2 was the lowest number I seen for half a second. 

[Mike4068]

That is exactly what you should be seeing. The alt only puts out as much power as the system asks for. Since music is dynamic the system only asks for more power when the bass gets heavy. There is a lag time between the request and the response. That is the reason for bigger and multiple batteries in larger systems. Your electrical is perfectly fine. 

[Kyblack76]

Wired at 2 ohm nominal,  your reactive load is shit, aka not much at all.  Where I dont really trust "a dude rebuilding a alt to "put out the max" , your draw is wicked low,... really. That board at 2ohm nominal, isnt pulling much... 

At 2ohm, on a 1500 board, I'd run stock alt, and just replace the battery with the largest I could fit & be done, and put the money else where. 

Also, when you build for nothing but full rpm out put, you do lose at idle. All alts can suffer from that,  from any maker. Get a decent full rpm load, and good idle, .. or idle suffers but higher rpm smashes. But, for what you got goin on, just run it. Holding battery rest and even higher like your doing (you aren't seeing 12s or 11s) dont sweat it... play it