minor alternator whine in 3kw system

I have minor alternator whine in my 03 Grand Caravan Sport. I have had 1200w to two 12" subs with no whine. I added a 1600w 4ch for the interior speakers and now there is a minor whine. Here is what I have (Collection over time, I know it's not good equipment): 1. Clarion NZ409 Head Unit 2. Sony Xplode 1200w 2ch amp 3. 2 12" Pioneer subs 4. 1600w 4ch amp (can't recall manufacturer atm) 5. Stock interior speakers 6. Rockford Fosgate 1 Farad Capacitor 7. 4 gauge power, distribution block 4 gauge before and after 8. 4 gauge ground, distribution block 4 gauge before and after 9. 16 gauge speaker wire for interior speakers 10. 3 sets gold plated, rca I have done the following to figure out the culprit: 1. I have redone the ground for the dist. block and ensured all connections are good. 2. I have grounded the rca's with no avail. 3. I have grounded the deck straight to the battery & to the amp ground both (separately) to no avail. 4. I have cleaned the battery terminals and connectors 5. I have also added a larger ground for the bat to chassis and larger alt to bat+, both with no change. Not even a reduction. What are your thoughts? (other than get better equipment, if something is wrong with the equipment then I'll replace it) What else can I do to find the culprit and fix it?Semper Fi,

SSgt Moose

USMC RET, 2x Iraq Vet

ground your deck to the closest piece of chassis in your car. make sure to remove paint and such. you're getting a ground loop between your amp and deck. both need to be grounded to the chassis. if you ground to battery or alternator you pick up all the noise in the electrical system.

On every amp in the system, turn the gain control all the way down.  Do you still hear the noise?

I have tried grounding the deck to everything. Tried grounding the rcas too. No improvement. I turn the gain down all the way and the sound is faintly still there.Semper Fi,

SSgt Moose

USMC RET, 2x Iraq Vet

if you turn the gain on the amps all the way down and it is still there then your nameless 1600W 4 channel is most likely to blame for the whine. probably something minorly wrong with it internally.turn everything off and then unplug the rca's from the 4 channel and turn the system back on, is the whine still there?

Just disconnected the rcas and put a ground loop isolator on one of them.   No whine. Connected the second set and it was back. Just need an isolator for the second set of rcas. Problem is covered, not fixed.Semper Fi,

SSgt Moose

USMC RET, 2x Iraq Vet

OK, so now I got rid of the whine (more masked it than fixed it), but now when the amps pull there is no dimming but I have noticed it seems to get quieter overall over time. I am charging my battery (assuming cap is charging too if needed) and thinking I am droping in voltage but I don't have a voltmeter. How can I figure this one out? Thanks for the help so far.Semper Fi,

SSgt Moose

USMC RET, 2x Iraq Vet

is the battery healty. it serves to filter out some of the noise from the alternator. the cap is still a load on the electrical system. as well as the items discussed earlier.The RIGHT way is the ONLY way.

The battery is a BIG filter - it is a GINORMOUS capacitor. A capacitor is NOT a load on the system (initial charging excluded). As a reserve of energy, its overall effect is to DECREASE the load or strain on the alternator. It's the same as a battery - the bigger the battery, the lower the overall load/strain on the alternator. Do you conclude the same? Think of when an alternator doesn't supply enough so the voltage dips and battery & cap discharge (supply the load). Sure - the alternator has to replace the lost charge plus the inefficiency - negligible on the cap (1%?) but maybe 20%-30% on the battery. Though the cap adds insignificant "reserve" to the battery, it still reduces the battery discharge, hence saving the battery recharge inefficiency. A bigger battery means less discharge depth, hence less recharge current. (But yes - same overall power/energy - less current over a longer period.) If that doesn't make sense - or if you pick any fault with my argument/reasoning, let me know. (Assuming OP ssgtmoose doesn't mind the hijack - within reason!) Note that I'm talking generally and simplified - and I'm stressing overall "added" load and alternator stress. [Not that I think alternators can be "stressed" - they are (or should be!) self limiting and be self protecting wrt to overloads (even shorts assuming the power diodes can handle it). But irrespective of that, (bigger) batteries & caps REDUCE so called alternator stress. (But a discharged cap (0V) is initially a short circuit when connected to a battery.)]   

You are definitely dropping in voltage. You have done as you thought as well, only masked the problem. While yes the isolators are removing most of the whine, they are also removing that section of the audio spectrum as well. The problem is your nameless amplifier. You are also quoting the peak power ratings of the amplifiers, get used to quoting the real power rating of equipment that is based in RMS (root mean square). It is a far better indication as to the real power of an amplifier.Top Secret, I can tell you but then my wife will kill me.