mushaus

Interesting stuff on the M.A.D. website. His arguments make alot of sense to me.

Thanks!!

Adrenolin

Actually.. they don't filter out noise. Lot of posts online say they do but they don't. All it's doing is storing power. To be honest here I'd suggest the Alternator be upgraded to a 100A or even 140A (not needed but good for future upgrades), a good high quality new battery and updated wiring between it all.

Do all that first and then, if needed, look into the capacitor. They should only be needed IF you need one. Also remember that you don't need it on both amps.. only the one powering the subs.

For a really good read on capacitors read THIS post. It deals with the whole 2nd battery vs capacitor thing but is a really good read.

Norm Peterson

Correct me if I'm off-base here, but I think that while a capacitor isn't a complete filter all by itself, it does smooth out the ripples (AC component) that can come through as noise. Storing more from the peaks and giving a little power back during the low times sounds a little like the electrical equivalent of a flywheel.


Norm

mushaus

After reading the information on the M.A.D. Enterprises I was planning to purchase a 100 amp, externally regulated (just like stock but with more amps). I was on the Mustangs Unlimited site poking around and noticed that the Voltage Regulators are only rated for 65 amps.
http://www.mustangsunlimited.com/ite...atkey=emustang

Do I need to update my stock voltage regulator as well?

4reboy

I agree with everyone else, get the 100 amp or else you'll have problems when running a bunch of electronics at once. and I don't believe you have to replace the voltage regulator, but if you do get a new electric version, not mechanical. at least thats what I did... haha

PReal

I am running roughly 350 watts rms on my 65 with orignal style alt with no issues. I consistantly have roughly 14 volts when charging.

One comment:

Capacitors are 100% useless. They are all marketing hype and provide no true benefit to your electrical system. They may make the dimming on headlights dissapear, but they create more of a drain on your charging system. If you understand how a cap works, then you should be able to understand that after discharge, the cap must reach full charge again in order to disperse energy. THe discharges and charging both happen in miliseconds, but after the 1 farad is gone, your amps are more starved then they were before.

In other words...

DO NOT BUY A CAP!!!


If you are having current problems there are a number of other ways to decrease the resistance of your chassis and increase the ability to current flow. The big 3 upgrade(replacing the charging wire, grounding from engine to battery, and grouding from engine to chassis) will really help a dimming headlight issue. A higher quality battery is also a great place to start. Optima's aren't too bad, I have 2.

fakesnakes

Mr. PReal, you have just made your own argument against yourself!

If you had an alternator capable of supplying the correct AMPERAGE not voltage your capacitor would work correctly. Caps charge and discharge based on the rc time constant (basically, resistance times capacitance). Connected correctly (in parallel and as close to the amp as possible), the rctc is low on the charge cycle and high on the discharge cylce. Meaning it charges almost instantaneously and discharges at a slower rate. This keeps those big bass notes that require significant current to move the speaker voice coil for a crisp, clean note fully fed.

If your alternator can not provide the current (your voltage reading means nothing) to satisfy the fast charging requirement of the capacitor, you will get exactly the symptoms you are decribing. Capacitors are not hype. Properly applied and fed, they are an important component of a good sound system.

PReal

I don't understand what is an argument against myself.

I did mention voltage, but a higher voltage means a lower current output across a given load. If my alt was having real problems keeping up it, the voltage would drop as the current increases.

99.99% of cap installs in cars is that they are installed in series, not parrallel with the amplifiers. They are simply connected on on the power wire.

So, my question to you is how long does it take for a cap to discharge. Running some quick calcs... The energy stored in a 1 farad cap is 72 Joules at 12 volts. Given 12V and lets say 30 Amps peak at load a 1 farad cap has roughly 0.2 seconds of energy stored for that situation. How many bass notes are longer then .2 seconds is relative to the music you listen to... After the .2 seconds your cap is 100% discharged and must recharge before another discharge. If the current requirement is less then the amount of energy you have stored, you still partially discharge the cap and need to fully recharge before another discharge. All of this of course assumes your wire is properly sized. But I';ve had beer and my decision making is a little skewed. Here is a write up that we provide a link to in the car audio section of the forums...

Linky...

http://3.8mustang.com/forum/showthread.php?t=176417

Quote (A lot of reading...)
"After studying a little history on large 1 Farad capacitors in car audio, you'd be amazed that they even sell at all. How useful are they? What do they really do? Will a Cap 'improve' my sound quality? Will it Prevent my lights from dimming? Will it audibly affect my audio system in any way?

Before you get the truth to any of the above questions, chances are, you've probably spent $100 or more on one of these devices. However, let's study a little history regarding this issue.

A long time ago, in a land far away, 2 elves...Ok, Richard Clark & Wayne Harris (Carsound magazine and the inventor of DB Drag, respectively) separately came up with a solution to preventing their lights from dimming.

WHO WERE THESE GUYZ?

As you may know, Richard Clark is one of the founders of autosound2000 Tech Briefs, Carsound magazine, and a published author of the industry of mobile electronics. In SQ competitions, he posted a record of 1234 1st place finishes, and only ended up NOT 1st in his first event. I've heard that he had minor system problems, but judging by his record, he must have corrected it. (evidently, he needed a Capacitor )

Wayne Harris was previously a leader at Rockford Fosgate in their development. Later, in his free time, he created the organization we call DB DRAG. Wayne was the first SQ World Champion from the organization we know as IASCA (International AutoSound Challenge Association).

Both of these gurus are both legends, and considered the leading experts in the field. During their competition days, both guyz came up with a way to assist in the prevention of voltage drops. In SQ competitions, the look of your system is actually more important than the sound, and having your lights NOT dim under high playing levels is a competitive advantage.

As you may know, an amplifiers is made up a battery of little capacitors, resistors, etc. What has been common engineering knowledge is that capacitors store energy, and more or bigger ones assist in balancing the power supply.

Wayne came up with the idea of putting several dozen 'little' (approx 100uF) capacitors on a circuit board to 'extend' the power supplies storage. At about the same time, or shortly afterward, Richard came up with the idea of one huge mondo capacitor (I believe it was 800,000uF or 0.8F) to do the job.

Eventually, Richard won. The large cylindrical tubes won over the complicated 48 caps strapped to a circuit board. However, what did this really accomplish? Let's start here:

WHAT IS A CAPACITOR?

Basically, capacitors are an energy storage device. Large, 1 Farad or more
capacitors store energy (electrons) between their plates. Capacitors differ
from batteries because batteries store energy in the form of chemical
energy--and rely on acid as the place of storage. For a more detailed
description of a capacitor, go here:

www.eatel.net/~amptech/el...raudio.htm

Then on the right hand side, scroll down to CAPACITOR. Keep in mind the use
of capacitors in an audio system.

WHY DO PEOPLE BUY CAPACITORS?

The number 1 reason would have to be because their lights dim when their
system is playing HARD. In car audio, we are told that a capacitor is
designed to prevent the voltage drop associated with your lights dimming.
The number2 reason is that it is rumored to 'improve' sound quality or
'stiffen' the power supply/source.

WHY DO MY LIGHTS DIM?

Headlights brightness is in direct proportion to the source voltage. For
instance, if your car is running, system voltage is ~12.5 -14.4 VOLTS. Your
lights will be much brighter than when your car is turned off--where battery
voltage is ~12V. Most car alternators put out between 75 to 120 amps of
current. When this current draw threshold of the charging system is
exceeded, system voltage will drop as power demands are now shared by the
alternator and the storage devices (battery & cap). We are using battery
reserves beyond this point until the demand lessens

When playing your system really hard. Your lights dim because your
alternator can't keep up it's charging voltage (around 13.8V) and therefore,
demand exceeds output. When this happens, your electronic devices are
dipping into the power storage of the battery. Since the battery stores
power at ~ 12-12.5V, there is a 1.3 to 1.8V drop in voltage available. This
in turn is why your lights dim down.

HOW MUCH POWER DOES A CAPACITOR STORE?

1 Farad = 100 joules or 100W/second
850cca battery = ~2,200,000 farads

For storage purposes, you'd need ~2,200 1 Farad capacitors to equal the energy of your battery.

Due to its impedence (ESR & ESL), a cap's energy is only 50% available. What's worse, is that in order for a 1 Farad cap to discharge, first the alternator output must have maxed out, and the voltage must have dropped around 1.5 volts. But I thought a cap was supposed to prevent that (voltage drop)!!!!!????? Yep, you got the point.


IF A BATTERY = 2,200 CAPS, THEN WHY BUY A (PUNY) CAP?

My question exactly. Marketing is the reason why people buy caps. In many cases, upgrading wiring will help your system get the maximum transfer of current. Once that has been reached, adding a capacitor may have a minor effect on your system. 50W over the course of a second is not a lot of power considering an amplifier may draw 2000W to put out 1400 watts. Let's look at the situation from a resources standpoint.

Alternator 80 amps
Car accessories (minus stereo) 40 amps
Car Audio system (DRAWS ) ~200 amps AT FULL OUTPUT

In this case, you have 240 amps of draw, but only 80 amps of current from the alternator. In your case, you need 160 amps x 12 volts or or let's say 1920 watts of energy. Since a cap stores 50W, how much of a difference do you think it's going to make? A cap is a peashooter, and we need a Howitzer 150 calibre cannon.

Also, Once a cap is discharged, where does it get it's power from? The alternator, which is already overloaded. Once a cap is discharged, it's worthless. Like justin says, “..The cap already shot its wad, an does limp til recharged…” you get the drift.

SO, WHAT IS A CAPACITOR GOOD FOR?

1. Audio Jewelry- impress chicks with large cylindrical shiny thingy
2. Extra weight in winter time
3. A very POOR... BUT expensive distribution block
4. A projectile in the event of a crash
5. Rolling pin--for cooking purposes
6. A neat thing to tell your friend, "..Hey man, lick the top of this..


Please do not try # 6. New hairstyles are always refreshing, but if you are wearing railroad tracks across your teeth, you might have one big filling after it’s over.

HOW CAN CAPACITORS IMPROVE SOUND QUALITY?

They can't. Sound quality is not dependant upon the presence of large bulky 1 Farad capacitors. How many 1 Farad Capacitors do you think the Boston Pops, Aerosmith, or Snoop dog use in the recording studio?

IN A NUTSHELL.......

When Richard, our fearless inventor, became World renown for winning every competition under the sun, people began copying what he did. Soon, every 'serious' competitor had a 'stiffening' capacitor--not to be confused with the 'loosening' capacitor.

WHY?

In the late 80s, people began sticking out their tongue when dunking the basketball because Michael Jordan did. Did sticking out your tongue improve your dunking ability? Same here with adding a capacitor to your electrical system.

STILL A GLUTTON FOR MORE PUNISHMENT?

Here's the Original Cap Debate.

www.carsound.com/ubb/Arch...00307.html

Phoenix Gold's marketing guru had just posted information on how their Powercore (basically the Alumapro CAP15 in a Phoenix shell) had both stabilized their voltage and improved the sound quality. Richard called him on it (all in another post) and the marketing geek was unable to quantify any of the conditions that resulted in the voltage being HELD at 14.2V and the 'improved' sound quality.

Please do not read every stinking post as valid. There are a lot of people that have had the efficacy of capacitors inbred to their minds, and were not (and still not) convinced in the futility of a 1 Farad storage device.

In a final note, Richard relayed a quote regarding battcaps ( www.battcap.net ) as, "..The audio industry is the only place i know of where you can publish specs that show your product is useless and still be able to sell them------and whats worse is that technically ignorant people will argue against the math!!!!!!!..............RC.." when referring to the product. This also relates to most digital readout capacitors."

mushaus

PReal, you could be right about the CAP but I do think I need to replace the stock alternator. I'm running 500 watts RMS, so according to fakesnakes calculation (500/12 = 42 amps) there wouldn't be much left on a 55 amp stock alternator for other things like headlights, tailights, gauges, etc.

PReal

My previous post is a handful. This is one of the largest areas of contempt in the car audio section of the forum and a constant point of discussion on every car audio forum in existance. CAP sellers are doing a great job...

You are correct.

Remember that power ratings at rms vary by the volume you are playing your system and the music you are producing at the time.

I already have an optima and upgraded wiring in my 65.

I will more then likely be installing a 3g alt in the future when I upgrade to electronic ignition and put my quality stereo in the mustang.