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thizzkid

Big 3 aquired, still having lights dim

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ok so i done some trouble shooting to figure out why im still getting voltage drops, light dimming, and why my subs turn off when i play heavy bass songs, and this is what i came across

so today i measured for bad grounds, first i measured the battery with the car off, 12.6volts.

secound i measured from the neg side of batt to chassis ground, got 0.01 as a reading on the DMM, so that means mininum resistance which is good right?

i turned my car on, turned on the wiper blades front and rear, turned high beams and headlights on, and put my heater on MAX

i put my HU to about 26/35 and measured the battery and it never went less than 13volts

so with everything still on, i measured the power cable and ground cable AT THE AMP, same reading 13-14 volts

this is the part where im confused, so with all that being done, my lights still dim, and when the heavy bass drops when im driving and listening to music, my amp seems like it cut offs, but the green light always stays on, so really its just my subs that cut off for like 1-3 seconds

so is it a bad ground at the amp? i have 17 feet of power cable and im running 1200 watts, do i need to upgrade my power wire to 2 gauge? Should i be worried that this will ruin my amp?

heres a little background info

-1995 ford explorer

-130-140 amp alternator

-BIG 3, 4 gauge everywhere

-4 gauge amp kit from ebay

-Hifonics BXI1210D 1200 watts at 1 ohm

-2 12" pioneer subs

-kenwood mpc 205 HU, 2 volt pre-outs

thanks guys for all feed back

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im guessing you have a bad ground to ur amp. also, u might want to run 0 gauge, just to be on the safe side. find out if ur alternator might be going bad too.

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I would start by redoing all of your grounds and doing the Big 3 with 1/0. I only run about 600 watts right now with factory alt but get no dimming lights at full tilt because I have done the Big 3 with double 1/0.

Andrew

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x2 on the Big3 in 1/0 and checking your alternator, mine showed the same warning systems before it completely went out. Any parts store like AutoZone or Advance would be happy to do it for free!

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thanks again guys for the help, so should i measure my amp ground with a DMM to see if its faulty? if so, please if you can do so nicely direct me on how to measure it.

do you guys think my amp will be alright? i dont want to loose my baby.

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Yeah, a BIG 3 isn't a BIG 3 without 1/0. Power wire can act in many funny ways....trust me. Keep your ground as short as possible and just make sure it's tapped to bare metal and firmly tight. Do the upgrade and then come back and let us know if problem solved. :)

Edited by ESW

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Check your O-rings the wire inside maybe loose. I like to solder all my wire inside the O-rings when doing the Big 3. Good Luck

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Do you have aftermarket headlight bulbs?

Your DMM I would be isn't fast enough to pick up the voltage drops. How did you set your gains?

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with the harbor freight tool DMM, i used that to set my gains, just turned the dial to 200 ACV and measured for 34.0

no aftermarket lights, just stock

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It definitely isn't picking up the drops. Ford Explorers are not notorious for having such sensitive bulbs so I'd imagine you are getting quite a drop.

As for the voltage you measured, it would be good to know the impedance of the load (ie calculated power). If you set the gains to the rating of the amp, you are into clipping as that amp will not do power without.

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It definitely isn't picking up the drops. Ford Explorers are not notorious for having such sensitive bulbs so I'd imagine you are getting quite a drop.

As for the voltage you measured, it would be good to know the impedance of the load (ie calculated power). If you set the gains to the rating of the amp, you are into clipping as that amp will not do power without.

ok so whats not picking up the voltage drop? my meter?

im at a 1 ohm load so 1200 watt rms at 1 ohm is 34.46volts

are you trieng to say that right now my amp and subs is clipping?

please explain clearer, thanks again though for the feed back

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The meter has a capacitive display. IE there is a time constant or smoothing that is occurring. In other words, really fast voltage spikes in either direction it won't see. Volts are dropping, you just aren't measuring it.

And yes, I am sure you are clipping your amp. No way that isn't at 1200w. On a real load with a distortion tester that amp will not produce its rated power. Set it at 1000w and see if your problem still exists. Conveniently for you, there is NO AUDIBLE difference between 1000w and 1200w anyways.

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so what should i do? if my DMM cant read voltage drops, how can i be able to even set my gain? whats the point in even using a DMM if my amp is clipping at the rated power it claims, and if so how would i know setting it at 1000 watts is really going to be set at 1000 watts if my meter cant read it?

from what every said about me set-up i thought i would be ok, but what your telling me is making me really nervous

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another thing i forgot to mention is that when i measured for voltage drops at the neg and positive post at the battery, not only did i use my DMM, i used my diehard 950 portable battery, with voltage display and i used it just like the voltmeter, placed the clamps on the post to measure voltage drops, and its reading was the same aswell, so out of curiosity do you think that the portable battery can detect voltage drops, or would it be in the same category as the DMM, which it cant read voltage drops since it has really fast voltage spikes? Heres the link to the pic of my portable battery to show you guys what im talkin about

picture

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The meter has a capacitive display. IE there is a time constant or smoothing that is occurring. In other words, really fast voltage spikes in either direction it won't see. Volts are dropping, you just aren't measuring it.

And yes, I am sure you are clipping your amp. No way that isn't at 1200w. On a real load with a distortion tester that amp will not produce its rated power. Set it at 1000w and see if your problem still exists. Conveniently for you, there is NO AUDIBLE difference between 1000w and 1200w anyways.

M5 I'm sure you know the answer to this, but the fact has slipped my mind at this moment. I think most DMMs recycle their reading 2-3 times a second and the good ones up to 5; but the human eye can detect a dimming light at 1/20th a second?

I tried my best to remember lol

Andrew

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so what should i do? if my DMM cant read voltage drops, how can i be able to even set my gain? whats the point in even using a DMM if my amp is clipping at the rated power it claims, and if so how would i know setting it at 1000 watts is really going to be set at 1000 watts if my meter cant read it?

from what every said about me set-up i thought i would be ok, but what your telling me is making me really nervous

You shouldn't use a DMM to set the gain, at least not at a level you aren't 1000% sure your amp can supply.

However the solution is in my previous post. Turn down your gains, you won't hear a difference anyways.

Conveniently for you, there is NO AUDIBLE difference between 1000w and 1200w anyways.

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All the info above is good. I would check your battery also. You said it was resting at 12.6V? That is a low battery and could be part of your problems as well.

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