Aftermarket Amplifiers and sever Dimming/Voltage Drops.

[rogue]

I installed an amp and sub in my 300c and am suffering an amazing amount of Voltage drops and Dimming. Are our alternators too small to handle the load? Or is it the 8g wiring they used on the grounds and the Big 3?

I am considering doing the Big 3 upgrade myself if it can be done somewhat easily, rather than have a shop charge me $250.

What have all of you that have installed aftermarket amps and subs done to correct this situation?

Did any of you upgrade your wiring FROM the Alt>Battery, Battery>Chassis, and Engine>Chassis yourselves?

My amp is rated at 1000 watts at 1 ohm.

Thanks for the help.

[Fred]

I would add a capacitor, and just use your 4ga battery to amp. Here's why: Alternator only delivers xxx amps (around 130 I think so you get the ORDER of magnitude) if you try to take more power FROM the alternator than what is available, you're just going to kill your alternator. If you have enough capacitive storage then when you get a few hard bass hits there will still be some juice left in the caps, acting as a buffer rather than drawing loads of power FROM your car's electrical system. On the more performance/practical side, If the alternator were able to transmit power at its full rated output quicker then it would keep thinkgs going good, so I would say your "big 3" upgrade wouldn't be a waste. I am sure that for stock performance it is not going to be a significant benefit in terms of ignition coils getting more power as DCX most likely tested all those factors in placing the battery and choosing wiring.

So the 1000 watts is that RMS or peak? What fuse(s) are on the amp itself? If it were a true full 1000 watts (input) that would mean a between 69 amps (14.3v rating) and 83 amps (12v). What are you driving at 1000/1 ohm, 2 DVC's at 4 ohm/coil? What amp are you using? Some amps have better prestage power input circuits and are more efficient than others and cause less dimming for similar power outputs.

[rogue]

The amp in question is a Hifonics Brutus BX1000D. It is a class D Amplifier. A bit over rated, but decent cheap power. I have it wired down to 1 ohm to a DVC 2 ohm Adire Brahma 15" Sub.

My understanding with caps is that adding one to an already strained electrical system only adds more strain. Its one more thing for the wiring and alternator to charge? Is this untrue?

[snickle]

That depends on wheteher system is always oertaxed or just has spikes. caps will help with spikes.

I do think our alternator is a little under powered, but that is what you get on a bargain car.

[Rev.Hammer]

The Magnum uses a 140 amp alternator.
Make sure the ground is as large as the power feed.
Buy a bigger ampacity battery and then add another just like it, wired directly to that battery and then connect the battery in the stock position normally to the charging system.
Wire the power feeds to the second battery.
Add in 1 cap per amp.
If THIS doesn't by-God solve it, go get an Iraggi alternator. The best there is!!

[67charger]

I have dimming and the dealer said it was normal. I had the service advisor stare at my interior lights for 5 minutes so he could confirm it for the tech (I hate it when the work ORDER comes back "condition not found").

Anyway, he said they could not find anything wrong and pulled another Magnum off the lot and it did the same thing.

It bugs me because I can see my headlights dim when I'm idling sometimes.

[Fred]

To address 67charger's concern: When idling with the headlights on you will notice occasional dimming, as the alternator's output rating is usually around 2k rpm not 650. It also cycles charging so it does not place a LOAD on the engine when not necessary. The only way to fix that (which WILL be done to the police version) is a retune with a higher idle. All police package vehicles (well the crown vic's anyways have the raised idle for all the equip like radios computer strobes etc)

[67charger]

Thanks Fred...that makes more sense to me than a shrug of the shoulders FROM the dealer.

[Fred]

Glad I could help clarify for you.

[Fred]

The Magnum uses a 140 amp alternator.
Make sure the ground is as large as the power feed.
Buy a bigger ampacity battery and then add another just like it, wired directly to that battery and then connect the battery in the stock position normally to the charging system.
Wire the power feeds to the second battery.
Add in 1 cap per amp.
If THIS doesn't by-God solve it, go get an Iraggi alternator. The best there is!!

Having dual batteries will help a lot, but you must wire the second battery to an isolator. When the two batteries are sitting in parallel and not being charged by your alternator, the battery with more charge will charge the lower battery. Since this is not a 100% efficient process, they will generate some heat (not noticable, but heat is wasted energy) they will eventually both go dead... Not instantly, maybe not for even a few days of sitting but they will put more wear on them (probably less than the system itself)

Basically, isolators are good practice for isntalls with more than 1 battery. The other benefit is you have the isolator set to keep the batteries seperate when the engine isn't running, you can pump the system and not worry about killing your battery cause the car's starting battery is not being used for it.

So in summary... Try the cap and see how you are FROM there... I have a Brutus amp also and it's great, 1 ohm stable rocks the house!

[henry]

Change the subwoofer LOAD to 4 ohms and the amp should draw less current. You'll likely notice no difference in sound output.

Henry

[Fred]

WHAT ::DROPS JAW:: The subs would get roughly 1/4 the power, why don't you just tell him to throw out his amp and get a Pyramid 200 watt amp? The Hifonics Brutus is rated for its power and stability at 1 ohm.

BUT!

Since the sub is a 2 ohm DVC you CAN try it out wired in series instead of parallel for actual testing rather than theoretical. Why it's possible that the amp isn't getting all the power it wants and then not hitting as hard as possible. Rewiring the sub is a nice 5 minute testing...

[henry]

It's not about power, it's about utilizing what you have.

Parallel voice coils will have 1 ohm impedance which will force the amplifier to put out four times the current than if you had the coils in series (4 ohms). This is hard on amps and most don't have the power supplies that can cope (even the ones that supposedly say they are stable at one ohm) Even the most robust power supply can't sustain current output INTO a short circuit. Now car amplifiers don't generally have the necessary design and stout componentry to drive a 1 ohm LOAD properly. They begin to distort at moderate volume and just make a mess of the signal.
Why anyone would want to drive an amplifier at 1 ohm is just beyond me. It makes absolutely no sense except bragging rights about "power output".

Speaker cone excursion is a funciton of voltage, not current. The voltage output FROM the amplifier would be the same.

[Fred]

Henry i am sorry but i beg to differ... Firstly an amp rated at .1% THD at RMS output rating INTO 1 ohm LOAD does not indicate a deficiency in the amp. It is a deficiency in the power delivery to the amp.

Speakers' rate of excursion is a function of wattage which is voltage AND current. If it were a matter of voltage with no regard for current then we could use 28 gauge bell (telephone wire) did you know when a phone rings it's 48+ volts? yeah so measly 12 volts? Under your reasoning then christmas tree tinsel would be sufficient. Well my buddy's stun gun that runs off a 9 volt battery cranks out 100,000 volts... That must make a lot of car alarms go off if he wires it to a subwoofer?

[bigkevin20]

This is what you need. Get a Optima Yellow top battery along with a Cap. You can get about 4 farrads or more off of ebay pretty cheap. You can get get a second battery and isolater but thats not needed in your situation. Also make your wire 4ga coming FROM that amp if its running at 1 ohm 8 is to small.