guages blink with use of subs need help!!!
 

:argh:Hey i have a 760w amp in my truck with 12'' subs and when my subs start bumpin i guess you could you say my guages blink and at idle my rpm's drop also my voltage guage drops every time the subs hit should i install a bigger alternator or could i go with a bigger pully on the alternator anyone had this problem any help would be great thanks!

Neither the alternator, nor pulley. You need a capacitor. They store and release energy very quickly. They are installed in parallel with the power cable going to your amp. The closer to the amp the better.:tu:

would that be why there is not a really fine point when it hits and how much does a decent one go for

that would be why! i got mine for $100 and it works great

wats a good brand

i used rockford fosgate, seems to be a good one to me but i'm not too into car audio though, i googled it and looked at the reviews of them and got one that everyone said worked good

I ran a Fosgate, and a Stinger at different times. I didn't notice a difference between the two. Stinger cost less. I strongly suggest you get a 1 Farad Cap, don't let someone undersell you into a 0.5 Farad.

sorry but wats the difference im new to subs

Farad rating is essentially how much energy it can hold. With your amp up to 15 feet away from it's power source, it takes a while for the power from the batteries to get to your amp. With a Cap close to your amp, it smooths out the power draw spikes. The alternator can't react quick enough to increase, then decrease it's output to satisfy the draw generated by the amp.
If you understand hydraulics, think of it as an accumulator.

alright thanks for the help i will stop at the pawn shop tomorrow:tu:

yes a 1farad cap is what you need:tu:

Before you going to throw money out of the window please tell me what cable diameter are you using?
How long is the wiring?
How old is the battery and which brand?
What kind of fuses do you use?
Your current draw is to big- that can have two causes:
a) wiring to thin (voltage drop)
b) battery worn out(internal resistance to high)

A capacitor will only cover up a bad supply. Fight the causes- don't try to cover them!

Read this:

http://thumbs.picr.de/6195801ryi.jpg


Seriously, the voltage drop is caused by the resistance of the wiring or from a bad battery. That explains your diming illumination. Have also in mind that the output of an alternator at idle speed is around 50% of the rated output.

the wireing is about 15 feet and the wire is a decent size plenty big and the battery is brand new before winter

Despite the good advice supplied, a capacitor is not a waste of money in my opinion. If nothing else, it will take away the constant on - off signals being sent to the alternator.

ok thanks for the help know i just need a place to put it lol running out of room

Where do you have everything now? :humm:

Decent size? Decent is no compareable unit:D, Which size?
Brand new? A lead-acid from Wally? Which capacity?

These informations are pretty useless, look at the size, brand and capacity.

Disconnect your battery and measure the voltage after 24 hours or more disconnected. Than you have the real voltage and the real indicator how good your battery is.

15 feet in- or excluding return? Where did you connect the return?

Did you measure the voltage while running the engine already?

Although this is a bit old...I'm still posting :)

On the Jeep I never had problems and I have ~1000w of class A/B power, less inefficient than class D and I never had problems with lights dimming.

In my opinion no capacitor needed, just a good battery and good wiring (1/0 gauge and good grounds). If you still have dimming, the Big 3 wiring upgrade is a good improvement. You add 1/0 wire from Alt to Battery (positive, fused), Battery to engine (ground) and Battery to Frame (ground).

I tend to agree with Deezel Stink3r... Find the problem instead of band-aiding it... I've always wanted to up the alternator amps and get a better/new battery (instead of K-Marts cheapest one)... The capacitor will just help save the equipment already in existence... And YES, no less than 1 farad... I want to say 1 farad is for 500 watts and under... 1.5 farad would be for 750 watts and under... 2 farad for 1000 watts and under... and so on... Don't quote me on that, but i THINK that's the easy way to figure on the farad vs. wattage...

My lights used to dim now and then on my truck, I changed both battery's to brand new 780cca and I have no problems at all now... I'm also only pushing about 200 watts in audio equip.

Good luck with your problem... Deezel Stink3r is pretty electronic savy - worth considering his advice... :w2:

Deezel Stink3r is correct and is giving great advice. In most vehicles you can NOT install any type of high powered audio and expect the thin factory wiring (as well as some of the aftermarket audio wiring kits) or even the factory rated battery/altenator to be able to carry the additional load placed on your charging system. In some cars, even just a high powered deck without any external amplifiers will cause your car's gauges/lights to dim, it all depends on battery size and condition as well as the gauge and quality of your wiring and the amperage of your altenator.

I have three class A amps in my car for a total of 1825w continuous @ 4 ohms 20-20,000 hz producing 168db of sound pressure with a max of .04% thd. One amp pulls a continuous current draw of 90 amps, one amp pulls 60 amps and the third amp pulls 30 amps for a total of 180 amps of continuous current draw on my charging system...

Prior to installing all of this audio the factory rated altenator for my car was 30 amps and the factory rated battery was 650cca...

I now run a 110 amp altenator with oversized heatsinks and a 1000cca under the hood. I have two more 1000cca batteries mounted in my trunk. I run 4 gauge many stranded wire (for low resistance) between my altenator and battery under the hood as well as from that battery to the batteries in the trunk. I short-ground my trunk batteries directly to the frame through the bottom of the trunk and I run a 4gauge ground wire back to the underhood battery. I also have two 1farad caps on my sub-amp and a third 1farad for the other two amps...

Depending on how long I keep the volume cranked, I can still make my lights dim as I simply draw too much current however, before I made the upgrades to my charging system I couldn't even get my music volume more than about a third as my amps would go into protect mode... and yes, that was with the caps

So do the caps help?.. Yes.. But only in short music spikes/peaks/bursts... caps will NOT solve a current overdraw problem on your charging system

sooo, celticnonic, you have a hybrid??? lmao just kidding man... sounds fun to install to me...

lmao no... that's in my car, not my truck ;)

168dB with only 1800w ? What kind of competition ? Measuring style ? Sensor used ?
Unless you measure inside the box, I'm having a very hard time believing.

EDIT: with 180 amps drawn from the electrical system (I'm assuming it's the max current consumption) you are around 70% efficiency, which is a cool dream for a Class A amp.

Oh so this has turned into a flame forum?

AdrianD, 1825w is the continuous rating of my amps at a 4ohm load at 20-20,000hz (925w of that is per channel which would take it to 2750w continuous at a 4 ohm load)... I never said they were all running in a 4ohm config as I do have two .5 ohm stable amps

you are correct in the assumption that 180 amps is max current draw

I am not here to pound my chest or to say "mine is bigger/better than yours" etc etc as it really doesn't matter to me whether or not you believe me and I have absolutely nothing to prove to you

The topic here is about someone having dimming issues whenever they turn up their audio volume... as a solution some are saying to place caps in line and some are saying to fix charging issues. I merely used my audio and charging system setup as an example of the issues I had with using caps prior to upgrading my charging system...

although they do help, caps will NOT fix an overdrawn charging system

agreed... :tu:

That was far from a flame my friend. Things that don't add up make people ask questions...same goes for truck power claims, for instance.

/offtopic.

i just got a heavy duty alternator when that happened and everything works good now

Anyone think it'd be a bad idea to run a separate AGM or SLA battery for the stereo system, use a battery isolator and mount the battery back right near the amplifier?

It'd allow you to run the stereo without idling the truck and you won't have to worry about a dead battery stranding you. Great for tailgate parties or at the beach.

Although I'm sure there's a drawback to my idea... Things always "sounded like a good idea at the time" and then a fire breaks out.

im sure it wouldnt be a problem just the battery would go dead everyon else

Hmmm,
real Class A amplifiers have a maxium power efficiency of 7% to achieve a permanent non switching output. Transfered into a 1825W system output this equals into a neat power consumption of 26.000W or 26kW and gigantic cooling surfaces to get rid of the convection heat!

How do you provide the needed power, Mr. Scott? :pca1:

any one ever wired up subs and amp to hoke stereo and if so how?

You could do a capacitor to remedy this, but you might look into an Optima battery also. Both would help greatly.