severe voltage drops?

[mrjoeyjiffy 10+ year member]

ok so my setup is as follows:

2001 tahoe

Big 3

rebuilt alt 190a(shitty at idle though)

stock battery under hood

yellow top in the rear

ok so my problem is that my voltage drops very badly during bass notes, especially at idle.

normally im at 14ish volts wise(my pioneer HU seems to read about .4v lower than what the dash reads) whenever im above 800 rpms or so, at idle im probably at about 12. but when a hard bass note hits i can drop to as low as 11 volts at idle, and it still can go as low as 13 when not at idle.

im getting pretty bad dimming if its a really bass heavy song and i have it cranked.

my sound setup is as follows,

nfinity reference 6022i 6.5 2-ways

Hifonics titan txi 4006

Earthquake PHD5000W

Pioneer DEH-P780mp

2 Jbl W12Gti MkII's

I bought the amp from a friend of a friend who has 2 120 mm fans mounted on top of it that keep it cool(when i had the fans unhooked, 10 minutes of max play would have the amp too hot to touch, with those fans on it stays very mildly warm. Ive heard they are pieces of shit, but it seems to get everything pretty loud, most people find it uncomfortable to listen to a loud volumes, so im assuming its working.

but my question is, does it sound like something else is wrong here? or should i get an isolater? any help would be appreciated.

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[Supergumby5000 5,000+ posts]

need a much bigger battery bank, assuming yer running that at 1ohm or lower.

 

[mrjoeyjiffy 10+ year member]

1.5 to be exact.

 

[king ranch 5,000+ posts]

put the yellow top upfront and throw a big batt in the back or maybe two

like a hc2400 or 2 stinger spv 70's

 

[mrjoeyjiffy 10+ year member]

so an isolater will not help?

 

[IDSkoT 5,000+ posts]

1.5 to be exact.

There's your problem. I didn't read what equipment you have (no offense), but that's definitely the problem.

Get a bigger battery bank, and make sure your current batteries are all charged / filled up.

If your amp is too hot to touch, he should've added a better heat sink.

 

[ARSkemp 10+ year member]

That amp make 3000W @ 2 ohms, right? if your trying to get anywhere near 3000w out of it you'll definitely want at least another battery.

 

[mrjoeyjiffy 10+ year member]

its no longer too hot to touch, it feels fine now that i have the big *** fans installed on it.

 

[Linkz 10+ year member]

get an alt that gives more apms at idle. Buy more batts for the back

 

[mrjoeyjiffy 10+ year member]

.... so i guess 2 more subs and another amp is out of the question for a long ****ing time, do you think this old *** looking amp really can pull that much juice?

 

[jbizzle 5,000+ posts]

You could possibly be clipping it.

 

[mrjoeyjiffy 10+ year member]

****, how do i find out if im doing that.

 

[king ranch 5,000+ posts]

how did u set the gains on the amp

 

[mrjoeyjiffy 10+ year member]

well the pre outs on my HU are 5v, the lowest gain setting on the amp was like 6v or so, so i started there, put my hu about where i thought would be about max volume and adjusted it by ear til i thought it was a bit too loud and might be getting distorted, then i backed it down a click, which seemed to be right at about 5v.

 

[king ranch 5,000+ posts]

only turn your hu up 75% of max vol and set gains like that