dimming issues with 4kw

[valin 10+ year member]

I am having severe dimming issues under power, and i'm only running at 1/2 power at the moment!

System specs:

Memphis 4kw at 1.8 ohms

2- DD9515's

2 Kinetik HC2400's

The big 3 is all done with 2/0 awg

- alternator positive to starting battery positive

- frame to engine block

- frame to battery negative

- frame to OEM chassis ground

I have run a 0 awg power wire from the starting battery to the two Kinetik rear batteries.

I have run 2/0 ground wires from each battery to the chassis in different ground locations, well sanded down.

I have run a 2/0 wire between both Kinetik 2400's for both power and ground.

I have run 0 awg from the Kinetik's to the 4kw, which is only wired at 1.8 ohms, so should be roughly 2kw at the moment.

When I put a load on the system, I am getting some severe dimming on music. My interior lights are **** near going out. WTF is going on? I do not have a voltage meter (it's on order) to see what the voltage is dropping to, but I know the voltage is charging at 13.8 volts when the vehicle is running without a load on the system. I am running the OEM alternator, which is 150 amps. I know it can't support the demand of the 4kw, even at 2 ohms, but the Kinetik's should be able to hold voltage.

Any ideas?

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[Pioneer~Saturn 5,000+ posts]

The weak link would be your alternator, check around for pricing on an alt for it (mechman, dc, etc)

 

[kfx450r 10+ year member]

I am having severe dimming issues under power, and i'm only running at 1/2 power at the moment!
System specs:

Memphis 4kw at 1.8 ohms

2- DD9515's

2 Kinetik HC2400's

The big 3 is all done with 2/0 awg

- alternator positive to starting battery positive

- frame to engine block

- frame to battery negative

- frame to OEM chassis ground

I have run a 0 awg power wire from the starting battery to the two Kinetik rear batteries.

I have run 2/0 ground wires from each battery to the chassis in different ground locations, well sanded down.

I have run a 2/0 wire between both Kinetik 2400's for both power and ground.

I have run 0 awg from the Kinetik's to the 4kw, which is only wired at 1.8 ohms, so should be roughly 2kw at the moment.

When I put a load on the system, I am getting some severe dimming on music. My interior lights are **** near going out. WTF is going on? I do not have a voltage meter (it's on order) to see what the voltage is dropping to, but I know the voltage is charging at 13.8 volts when the vehicle is running without a load on the system. I am running the OEM alternator, which is 150 amps. I know it can't support the demand of the 4kw, even at 2 ohms, but the Kinetik's should be able to hold voltage.

Any ideas?

Do you have a highs amp? Using a winch? (lol) i wouldve said you need another battery but your running at 1.8 ohms. BUT ive heard the memphis 4kws draw alot of power.

Normally 2k wouldnt demand a bigger alt (although recommended) but it could be going bad or something.

 

[alvitae 10+ year member]

Have your batterys load tested by someone who has a tester for agm batterys.

A bad battery can be a big power draw.

 

[valin 10+ year member]

The weak link would be your alternator, check around for pricing on an alt for it (mechman, dc, etc)

I know that my alternator will not produce enough power to keep up with the current draw but shouldn't the two HC2400's produce enough to power to not even require the alternator's additional power?

Have your batterys load tested by someone who has a tester for agm batterys.
A bad battery can be a big power draw.

I will have it tested. Thanks for that tip.

 

[soundstreamer 10+ year member]

Run ground wire(s) from the front battery to the back batteries.

 

[ARSkemp 10+ year member]

Honestly, i dont think your lights should be dimming that much with your electrical. I have a stock alt in my escape (105-110 amp) + a HC2400 up front and 2 d3100s in back. I have absolutely no dimming running my AB500 @ 1 ohm and even @ .5ohm my voltage drops no lower than 13.

I would wait for the voltmeter to see what its dropping to before doing anything else.

 

[valin 10+ year member]

Run ground wire(s) from the front battery to the back batteries.

I was thinking of doing that, and will run a stretch of 2/0 to the back batts from the front batt. Hopefully that makes a difference.

 

[old_skool]

You certainly have enough current available but your voltage is dropping way low. Put a large capacitor in the system and you will see a huge difference.

 

[MisterGrubbs 5,000+ posts]

First off, The Memphis 4kw is a hog ******* bastard of an amplifier.

Your alternator, even though it's 150 amp, SHOULD be upgraded. BEST CASE if those batteries will hold the charge, they're going to die quickly without much backing from the alternator. Long term ill effects to the alternator or battery is possible, although unlikely.

You need to check resting/charged voltages on those batteries as well as your stocker. You might have a bad battery somewhere.

 

[anj46907 10+ year member]

I know that my alternator will not produce enough power to keep up with the current draw but shouldn't the two HC2400's produce enough to power to not even require the alternator's additional power?



I will have it tested. Thanks for that tip.

having the batts wont make a difference if you dont have a Alt that can keep them charged up. you may have killed the batterys running it like that you may want to start by checking the batterys. also ground out ure rear batteries to the back, dont run a ground all the way to the front. more then likely your soulution will be a better Alt and possibly a dead battery

 

[Xprime4 10+ year member]

Batts help alot with the voltage drops. I'm running over 2800watt rms on a stock 90amp stock alty with a stock 60ah and rear agm 110ah batt. I ain't dropping lower than 12.5v.

if it drop too much, lower the bass few minute to let the alty charge some more. is everyone listening to 140db + bass 24/7? I mean, i charge when i get into traffic/stoplight

 

[MisterGrubbs 5,000+ posts]

It is my goal to have people stop before the redlight or quickly turn because they know I'm coming and dont want to hear my bassssssssssssss.

 

[AlterEgo99 5,000+ posts]

Batts help alot with the voltage drops. I'm running over 2800watt rms on a stock 90amp stock alty with a stock 60ah and rear agm 110ah batt. I ain't dropping lower than 12.5v.
if it drop too much, lower the bass few minute to let the alty charge some more. is everyone listening to 140db + bass 24/7? I mean, i charge when i get into traffic/stoplight

I'd agree with that...I replaced my OEM AC Delco 78mA with a Kinetik HC 2000 102mA...fixed. The "Big 3" probably helped as well. I'd also like to swap out the 4 gauge OEM wire running from the fuse block at the battery to the electrical harness/fuse bank under my hood to 0 gauge at some point.

 

[Techchild 10+ year member]

You certainly have enough current available but your voltage is dropping way low. Put a large capacitor in the system and you will see a huge difference.

Great advice right here.