ok so i have a 86 mustang gt. i have a 10 inch kicker sub that's rated at 4000 watts. i was wondering a couple of things, first if i get a 500 watt dual amp and bridge it to the sub will i be able to notice a difference in sound quality? and can my stock alternator handle this? i also have a kennwood head unit. its pretty ****ty but i don't want to change it right now. please give me any feedback. thanks

 

What model sub do you have, dual or single voice coil, 2 ohm or 4? I can pretty much guarantee that it's not 4000 watts. By dual amp do you mean brand or 2 channel? Stock alternator is fine on 500 watts and the head unit should be good as long as there is a rear or sub pre-amp output (red and white inputs on the back).

 

Just look up the amperage output of your alternator and add things up to see if you really need to upgrade. For example, that 500watt amplifier should take no more than 500 divided by 13.8, which means it will draw 37amps max.

The output of the alternator should go beyond 30% of your total draw for everything, including OEM items (HVAC, lights, etc). If this is all your doing then I wouldn´t worry about it, 1 500watt amp isn´t going to tax the system.

If this is going to be a larger set-up later, then think about doing the big 3 upgrade to cheaply support what your doing as well as keeping the alternator output in mind.
May find you wish to do the above after even this minor upgrade, as insufficient or faulty grounding is usually the issue with flickering lights and other problems along this line, especially with older vehicles wiring due to corrosion.

 

You are assuming 100% efficiency and NO amp is 100% efficient. I've owned amplifiers that drew as little as 50 amps to make 500 watts RMS as well as one old school beast that drew 95 amps to make 500 watts RMS.

It all depends on the amplifier chosen for the job.

The Big 3 is not the miracle cure that most make it out to be, but I do agree with the tackling those grounds. The reason I agree with the grounds comes from a factory flaw where many automotive manufacturers choose to attach the factory grounding points to a painted body panel. I know one electrical engineer who takes every new vehicle he purchases and he wire brushes the paint off the body panels where the factory, under the hood grounding points are. Afterward, he applies Kopr-shield (copper infused permatex) to protect the connection. That step alone has managed to give him an in-vehicle reading of .2 to .5 more volts and he SWEARS by his methodology.

Back to my comment about the big 3 not being the miracle cure... I often see the analogy where they compare the Big 3 to a water hose. Increasing the diameter of the hose, i.e. the bigger cable, allows for water to flow more freely, i.e. less electrical resistance. Unfortunately, you are still stuck with the same old pump, i.e. your stock alternator, which is not capable of increasing your water flow, i.e. giving one more amperage.

 

I´m assuming it´s not complete trash, yes. It´s the average draw that´s at issue anyhow. Peak is not what the alternator has to deal with. This is also assuming 100% use of the amplifier´s output, so it´s doubtful to be more than that on an average basis even at use near full volume unless it´s absolutely horrid for it´s conversion.

True, but there´s no point shelling out for things that are very likely not needed, as I´m assuming due to the questioning this will likely not even be a truly 500watt RMS rated unit.

Never said anything about it being a miracle cure. Just simply something usually good to do to eliminate faulty or insufficient grounding in most cases. If the alternator can´t cope with the draw, extra grounding obviously won´t help. To use the analogy, having a larger hose isn´t of much use when all the water has been used.
Having done this with good wiring for the amp and it´s ground, and you still get major flickering with the headlamps, or the like, it should be easily apparent without needing to hook up an ammeter that the alternator probably can´t cope. So long as the battery itself is rated high enough, and it´s good.

I swear more by going over the connections when purchased, and once every year or so myself unless steps are taken as you mention to shield the contact points and wiring itself from the elements. Often times water gets into them at certain spots, the contact points themselves become corroded, and usually the factory done wiring is only sufficient to pass their own minor QA department. Not usually as good as it could be out the door from the factory, let alone 10-20 years later. This is even excluding the scenario you mention with not getting great grounds at the contact points due to paint and such. Which I agree with, as I´ve seen that in the past as well. Resistance is the enemy.

 

ok thats good to know that my altanator will handle it. my sub is from the 90's im not sure wat year it is. this set up it what im gunna stay with i have another sub same kind and year that im gunna hook up with the 500 watt amp but thats all the extra system im doin. Dual amp is the company

 

fox bodys are notorious for undersized electrical... big3 will help alot in a foxbody as an owner of more then one i can attest to it. also when ur alternator bites the dust do the 3g upgrade

 

ok so now that i know that my car can handle it, will it make a difference in sound quality. i cureently have just the one 90's kicker sub hooked up to a 125 per channel watt amp thats bridged

 

I wouldn't be concerned with sound quality running a dual amp (honestly it's not a great brand). If you're worried about how it's gonna sound I would get a little bit better quality amp with the right amount of power to run those particular subs (if you do get one make sure it's putting out the power at the ohm load your subs will be wired to). You could probably find a decent one used for around $100. If you are underpowering the subs you will most likely crank the gain up to make it sound louder which will make them sound like crap and possibly blow your subs. Having the correct size enclosure for the subs will also affect the quality of the sound.