# subs making a constant heart beat sound



## JThug69420

i have two 12 inch Xplods plus a 1200 watt Xplod amp and an aiwa head unit but anyway to the point my subs are making a weird thumping like a constant heartbeat. When i turn my car on or just my key the heartbeat sounds starts and it'll keep doing through out the song but you can't hear it cause of the music and when the cd wants to go to the next song it does it but when the music playing they hit really great its just that heartbeat sound i wanna get rid of. The subs are new and the amp is new the head unit is old. A buddy of mine told me that it could be my alternator could that be it?


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## hometheaterguy

Add a cap.


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## dr hypothesis

First things first, check ALL connections. RCAs, grounds, everything... Make sure nothing is loose. I doubt that Sony amp pulls much juice. If your lights are dimming bad, then yes you could use a new alternator.


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## hometheaterguy

Dr. would you not first test the alternator? Why spend a grand on a hi-output alternator and the bracket kit if a $100 capacitor would stablize the power?


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## dr hypothesis

Caps are useless. Don't know of anyone who uses or recommends then myself. They're just another strain on your electrical system. $1k for a high output alt? I picked up a 200 amp for $500.


If you're going to run a lot of power, an alternator is the BEST upgrade you could possibly make. It takes power to make power. I have 4 batteries in my trunk as well, as I'm running 4,500 watts RMS.


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## hometheaterguy

Now I know your not a doctor, LOL. Caps do not put another load on the vehicles electrical system, who told you this? Optimas do. OK, then $500 on a hi-out alternator. The best is the "ABC's of car audio" as was printed in a Car Audio and Electronics mag article. Alternator, Optima battery and caps. You can never get enough capacitence. Any ISASCA winner has had and still had lots of caps.


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## dr hypothesis

I have many friends who compete in dbDrag and Bass Race (part of dbDRag). Been on the Termpro forum for over 6 years. Go ask them what they think of caps.


Ask someone like Randy Kubek, Tommie McKinnie, Steve Meade, or other people using over 20,000 watts rms how many caps they use. These are also daily systems and demo/bassrace built vehicles, built to play music for long periods of time, not just a single note.


Extra batteries will provide MUCH more current then a cap could ever do. What charges the cap? The alt does. The cap constantly discharges and then charges. How is that going to hold up with constant bass? It's not going to do much of anything. But again, what do I know.










Optima is not the king of batteries anymore. Powermaster, Kinetic, NSB, among MANY MANY others. We're talking $2,000 batteries.


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## dr hypothesis

Just to reply to my reply, haha







...


Here's my situation: I've got a Memphis Mojo 4kw on my subs, and an Orion 400.2 on my components in my doors. The Mojo at full tilt will pull anywhere from 400-600 amps of current. If I could fit two alts under my hood, I'd do it. (A friend keeps suggesting it) A 200 amp alt is going to get really overworked, that's why I have as many batts as I do. Each Optima is good for 100 amps of current. I have NO light dimmage at all and I run my system HARD. I'm addicted to bass.







Been that way for seven years.


After awhile of hard pounding my voltage will drop in the low 12s, then I take it easy on my system. Let the alt catch up and I'm good to go.


Back in the day when I had an 89 Ford Ranger with I believe a stock 60 or 75 amp alt, I picked up a cap. Never hooked it up as all the advice I got was to upgrade the alternator first, after that if I needed it get extra batteries. Never looked back since.


I'm sure some people do use caps, but of all the medium to large to HOLY MOTHER OF GOD setups, I've never seen anyone use a cap. Anytime I see a question regarding them on Termpro (the forum for dbDrag) they always say not to use them.


As for INSANE, this is Randy Kubeks truck with 20 15s:


http://www.youtube.com/watch?v=y75AlxOTNQk 

http://www.youtube.com/watch?v=gxI73f0AoPM


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## MegaHurtz83




> Quote:
> Originally Posted by *hometheaterguy* /forum/post/11454833
> 
> 
> Now I know your not a doctor, LOL. Caps do not put another load on the vehicles electrical system, who told you this? Optimas do. OK, then $500 on a hi-out alternator. The best is the "ABC's of car audio" as was printed in a Car Audio and Electronics mag article. Alternator, Optima battery and caps. You can never get enough capacitence. Any ISASCA winner has had and still had lots of caps.



Caps most certainly put a load on the electrical system. How could you explain that one away? Having to charge the cap is going to be a load. Anything in the electrical system is either going to drain power or supply power. The only things supplying power in your car are going to be your alternator or your battery (if the vehicle is off). Anything else is a load.


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## MegaHurtz83




> Quote:
> Originally Posted by *dr hypothesis* /forum/post/11455553
> 
> 
> I have many friends who compete in dbDrag and Bass Race (part of dbDRag). Been on the Termpro forum for over 6 years. Go ask them what they think of caps.
> 
> 
> Ask someone like Randy Kubek, Tommie McKinnie, Steve Meade, or other people using over 20,000 watts rms how many caps they use. These are also daily systems and demo/bassrace built vehicles, built to play music for long periods of time, not just a single note.
> 
> 
> Extra batteries will provide MUCH more current then a cap could ever do. What charges the cap? The alt does. The cap constantly discharges and then charges. How is that going to hold up with constant bass? It's not going to do much of anything. But again, what do I know.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Optima is not the king of batteries anymore. Powermaster, Kinetic, NSB, among MANY MANY others. We're talking $2,000 batteries.



I'll speak. I have a car that ran about 20,000 watts. We never had a single cap in the thing. Our car was running 12 amps and we used 16 batteries, a combination of 8v and 6v in a series-parallel configuration. It would burp over 170dB and drop about .1-.2v. We are building a new setup, we are going to be running 4 10kw amps. Again we won't have any caps, we are going to be replacing the 6v batts with 8v's so that we can run a 16 volt system.


Our other car which serves as a demo vehicle runs also runs a 10kw amp. It also has an 8v and 6v battery setup in the back, with 8 batteries in total. This car is the one that we park in our booth at shows and demo all day. We plug it into the charger the night before and these batteries will run this 10kw amp all day long.


And there are definitely better batteries out there than Optima. Those ones that you mentioned would all blow the yellow top out of the water. Personally, we are Exide dealers and their 34XCD "Purple Haze" battery has been torture tested and we've proven it to put out far more than a yellow top would.


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## hometheaterguy

Long live the cap, a thing not just of the 80's:



Why Add a Capacitor?  The overall response of your audio system will be enhanced with the use of capacitors due to their ability to store a large amount of power and discharge it quickly to supplement your amplifier's power supply during high current demand (low bass). It can also filter AC voltage induced in the system which could cause objectionable noise. A one Farad capacitor is recommended for each 1000 watts of amplifier power.
http://www.mmxpress.com/power_capacitors.htm 






Audio equipment, for example, uses several capacitors in this way, to shunt away power line hum before it gets into the signal circuitry. The capacitors act as a local reserve for the DC power source, and bypass AC currents from the power supply. This is used in car audio applications, when a stiffening capacitor compensates for the inductance and resistance of the leads to the lead-acid car battery.
http://en.wikipedia.org/wiki/Capacitors 




A stiffening capacitor (aka power cap or car audio capacitor) is a car audio component designed to provide power during times of peak load. The large capacitor acts as a energy reservoir for the audio system.

[edit] Explanation

The power capacitor, usually 1 to 5 farads, is connected in parallel between the battery and the amplifier. Multiple capacitors can be connected with busbars to reduce resistance and power loss. The capacitors are physically large and are often decorated with graphics or enclosed in an attractive housing, often with readouts to monitor the capacitor's voltage.

It can only hold a small charge, so a single bass hit can empty it completely. It charges back up when there isn't a large power demand. This makes it inappropriate for systems that will require prolonged delivery of power, as the capacitor cannot supply additional power, only store it temporarily.
http://en.wikipedia.org/wiki/Stiffening_capacitor 



Talk:Stiffening capacitor

From Wikipedia, the free encyclopedia


Jump to: navigation, search

How many capacitors would be recommended to run 2 high end amps?

I have read a few pages on the net that suggest 1 Farad per 1000 Watts of amp power. 65.17.135.54 22:05, 17 February 2006 (UTC)


[edit] Twaddle park

In high power audio applications the amplifier can require more current than can be supplied by the car battery, because of the battery's discharge characteristics. The slow power delivery can result in poor sound quality, dimming of the car's lights, or other electrical maladies. For audio applications that only require short bursts of power, such as a thumping bass line, it is more economical to install a power cap than to upgrade the car's electrical system. --Light current 22:36, 10 August 2006 (UTC)

Wiring removed from page:

A power cap will not help if an audio system requires more power than the vehicle's electrical system can deliver. While this usually requires upgrading the car's battery or alternator, a low-cost improvement is to upgrade the "magic three wires." Using thicker wires can increase the current capacity of the system. The three wires are:

the wire from the battery's negative terminal to the car's chassis (ground).

the wire from the alternator to the battery's positive terminal.

the wire from the chassis (ground) to the engine.

These three wires are often small and need to be upgraded when a high-power audio system is installed. Fixing this common bottleneck is low-cost, and is effective for powering a stereo while preventing the voltage from dropping and the headlights from dimming. --Light current 22:40, 10 August 2006 (UTC)




Talk:Stiffening capacitor

From Wikipedia, the free encyclopedia


Jump to: navigation, search

How many capacitors would be recommended to run 2 high end amps?

I have read a few pages on the net that suggest 1 Farad per 1000 Watts of amp power. 65.17.135.54 22:05, 17 February 2006 (UTC)


[edit] Twaddle park

In high power audio applications the amplifier can require more current than can be supplied by the car battery, because of the battery's discharge characteristics. The slow power delivery can result in poor sound quality, dimming of the car's lights, or other electrical maladies. For audio applications that only require short bursts of power, such as a thumping bass line, it is more economical to install a power cap than to upgrade the car's electrical system. --Light current 22:36, 10 August 2006 (UTC)

Wiring removed from page:

A power cap will not help if an audio system requires more power than the vehicle's electrical system can deliver. While this usually requires upgrading the car's battery or alternator, a low-cost improvement is to upgrade the "magic three wires." Using thicker wires can increase the current capacity of the system. The three wires are:

the wire from the battery's negative terminal to the car's chassis (ground).

the wire from the alternator to the battery's positive terminal.

the wire from the chassis (ground) to the engine.

These three wires are often small and need to be upgraded when a high-power audio system is installed. Fixing this common bottleneck is low-cost, and is effective for powering a stereo while preventing the voltage from dropping and the headlights from dimming. --Light current 22:40, 10 August 2006 (UTC)
http://en.wikipedia.org/wiki/Talk:Stiffening_capacitor 



ABOUT AUTOMOTIVE POWER STIFFENING CAPACITORS

by: affordable_quality_audio( 1088)

49 out of 54 people found this guide helpful.

Guide viewed: 3734 times Tags: Digital Cap



ABOUT  POWER STIFFENING CAPACITORS

WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.

 

WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!

IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.

 

WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!

IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

HOW DO I CONNECT THE CAP?  AND WHERE?

The capacitor should be connected as close to the woofer amp(s) as possible with the MINIMAL amount of cable length between the capacitor and the amp(s).  Heavy guage wire should be used for ALL connections and if using crimp type ring terminals for connections, all crimps must be tight and secure.  Solder the connections if possible for best results.


IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.

 

WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!

IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

HOW DO I CONNECT THE CAP?  AND WHERE?

The capacitor should be connected as close to the woofer amp(s) as possible with the MINIMAL amount of cable length between the capacitor and the amp(s).  Heavy guage wire should be used for ALL connections and if using crimp type ring terminals for connections, all crimps must be tight and secure.  Solder the connections if possible for best results.

 


IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.

 

WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!

IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

HOW DO I CONNECT THE CAP?  AND WHERE?

The capacitor should be connected as close to the woofer amp(s) as possible with the MINIMAL amount of cable length between the capacitor and the amp(s).  Heavy guage wire should be used for ALL connections and if using crimp type ring terminals for connections, all crimps must be tight and secure.  Solder the connections if possible for best results.

 



IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.

 

WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!

IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 

HOW DO I CONNECT THE CAP?  AND WHERE?

The capacitor should be connected as close to the woofer amp(s) as possible with the MINIMAL amount of cable length between the capacitor and the amp(s).  Heavy guage wire should be used for ALL connections and if using crimp type ring terminals for connections, all crimps must be tight and secure.  Solder the connections if possible for best results.



IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.

 


WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge.




WHAT DOES THE CAPACITOR DO?

The capacitor stores a charge that is supplied from the battery via a cable.  When you amplifier demands instantaneous high levels of power the cable cannot always supply it. 

Think of the cable as a water pipe.  If amount of water that can come out of a pipe depends on it's size.  The smaller the pipe, the less water,  the bigger the pipe, the more water. 

The power cable from the battery can only supply a limited amount of current depending on it's size.  Adding the capacitor close to the amplifier overcomes the limitations of the power cable by supplying the surge currents from it's stored charge



WHY DO I NEED A CAPACITOR?

Your car's electrical system typically is designed to run at 70% of it's capacity.  when you install a subwoofer amp, that amp can draw more current than any single component of the original vehicle's electrical system!

1) If you have ever seen your lights in the vehicle dim during high bass levels, that is a SURE sign that you need a capacitor.  Dimming lights indicates that an amplifier is drawing more current surge than the power supply system can deliver.  Dimming lights can also be caused by too small of a power wire that supplies +12VDC to the amp or a small or poor ground connection (see WHAT DOES THE CAPACITOR DO? above).

2) High current surge demands on your vehicle's electrical systems caused by amplifiers can damage the electrical system, including the battery, alternator and voltage regulator.  If the regulator or the alternator start going bad you will start to hear a "whining" noise in the speakers.

3) A law of Physics, called Ohm's Law shows that as voltage decreases, current increases. ALL WIRE HAS RESISTANCE no matter how big it is.  As more current flows through the power wire the resistance increases.  When resistance increases the voltage drops (see water pipe example above). WHEN VOLTAGE DROPS YOUR AMPLIFIERS WILL TRY TO DRAW MORE CURRENT!  When this voltage drops distortion will increase.  This is the #1 reason for blown amplifiers and woofers!


IS IT BETTER TO HAVE ONE BIG CAPACITOR OR SEVERAL SMALL ONES?

The answer to this one is simple... Several small ones.  Why?  If you look at specification on a capacitor you will see an ESR rating.  This is short for Equivalent Series Resistance.  Simply put it means how much it resists the flow of current into/out of the capacitor.  The smaller the number the better.  Bigger capacitor typically have a bigger ESR rating and therefore it will not charge as fast or output the needed current as fast.  For those bass notes we need something that can deliver the current to our amplifier quickly and then recharge quickly!

If you refer to the water pipe example above, consider a larger ESR rating the same as a smaller pipe fitting on the capacitor.


HOW DO I CONNECT THE CAP?  AND WHERE?

The capacitor should be connected as close to the woofer amp(s) as possible with the MINIMAL amount of cable length between the capacitor and the amp(s).  Heavy guage wire should be used for ALL connections and if using crimp type ring terminals for connections, all crimps must be tight and secure.  Solder the connections if possible for best results.


THE BOTTOM LINE........LOSS OF POWER CAUSES DISTORTION, BLOWN AMPS AND WOOFERS. 

Capacitors help to overcome this problem.
http://reviews.*********/ABOUT-AUTOM...:-1:LISTINGS:1 


2.9 What is a "stiffening capacitor", and how does it work? [JSC]

Stiffening Capacitor (note capitals) is a trademark of Autosound 2000. However, "stiffening capacitor" (note lowercase), as a generic term, refers to a large capacitor (several thousand microfarads or greater) placed in parallel with an amplifier. The purpose of doing so is to provide a sort of reserve power source from which the amplifier can rapidly draw power when it needs it (such as during a deep bass note). The electrical theory is that when the amplifier attempts to draw a large amount of current, not only will the battery be relatively slow to respond, but the voltage at the amplifier will be a little lower than the voltage at the battery itself (this is called line drop). A capacitor at the amplifier which is charged to the battery voltage will try to stabilize the voltage level at the amplifier, dumping current into the amplifier. Another way to think about it is that a capacitor in parallel with a load acts as a low pass filter See section 3.10 What is a crossover? Why would I need one? [JSC], and the voltage level dropping at the amplifier will appear as an AC waveform superimposed upon a DC "wave". The capacitor, then, will try to filter out this AC wave, leaving the pure DC which the amplifier requires.
http://www.mobileaudio.com/rac-faq/rac-faq_2.html#SEC21 


2.9.1 Do I need a capacitor? [MZ]

Before installation, it's often difficult to predict whether or not a capacitor will be beneficial to you. It's generally best to install the audio equipment prior to making the determination, so that you can address which symptoms need to be remedied and assess the severity of the symptoms. This will not only help you decide whether or not you need a capacitor, but also how much capacitance would be beneficial.

The most common symptom in need of added capacitance is headlight dimming (and sometimes dimming of the interior/dash lights). It's caused by a drop in system voltage associated with excessive current draw. While there may indeed be several loads drawing substantial amounts of current from the electrical system (eg. heat, AC, and so forth), it's usually the transient draws that best manifest themselves in noticeable dimming. This is partly because our visual systems are most sensitive to detecting rapidly changing intensity levels rather than steady absolute differences.

Once you've assessed whether or not the dimming is noticeable (and sufficiently annoying), you must decide whether a capacitor is warranted or if you'd be better served by upgrading the alternator. After initially having your alternator and battery checked out (some places will do this for free), the choice should be based on the severity of the dimming.

A commonly-used estimate for determining the appropriate size capacitor is 1F/kW (one farad per kilowatt). For example, a system running at 300W would need a 0.3F (or 300,000uF) capacitor. However, there are several variables at play here, including the capabilities of the vehicle's electrical system (which generally varies from idle to higher RPMs), the efficiency of the amplifiers, and the listening habits of the user (ie. the tone controls and the type of music). These factors should all be considered when making the determination. Moreover, the voltage drop can be so severe that added capacitance is nothing more than a band-aid. That is, even several Farads of capacitance would not be able to sustain the voltage for as long as the drop persists. This is when an alternator upgrade may be in order.

2.9.7 Will my bass response improve by adding a capacitor? [MZ]

A capacitor serves to smooth the voltage fluctuations associated with transient current draw. As a result, the supply voltage presented to the amp during peak demands tends to be slightly higher than without the capacitor. For most amplifiers, this will increase the power output of the amplifier during transients. The degree to which it increases, however, typically leads to an inaudible improvement.

To illustrate, if you consider an amplifier that delivers 100 watts at 14v and 80 watts at 12v (these numbers are somewhat typical), the difference in output from the speaker will be at best 1 dB when the supply voltage fluctuates from 14v to 12v. However, when you take into account the fact that no practical amount of capacitance can completely eliminate this voltage drop during transients, the difference in output becomes even less pronounced. Further, if you take into account other factors such as loudspeaker power compression (discussed elsewhere in the FAQ), the equivalent series impedance of the capacitor, the length of the transient, and the human's decreased ability to perceive differences in intensity for shorter intervals, this difference in output becomes negligible.

2.10 When should I upgrade my battery or add a second battery? [IDB]

The battery is most important when the engine is turned off, because it supplies all of power to the audio system. The stock battery in your car may not be up to the task of running a stereo with multiple (or large) amplifiers if it can't supply enough current to the amplifiers. Upgrading your current battery to a larger model may help solve the problem because batteries like the Optima 800 offer a larger number of cold cranking amps.
*Generally, adding a second battery is great if you want to listen to your stereo with the car turned off (and be able to start the car again later!). This is accomplished using a dual-battery isolator: a device which allows the second battery to be charged by the alternator, but prevents the amplifiers that are connected to the second battery from drawing any power from the main battery. Installing a second battery may be done instead of upgrading the main battery.*



www.mobileaudio.com/rac-faq/rac-faq_2.html


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## schticker

This forum is absolutely the worst when it comes to getting off track.


OP - Here's the deal. Your amp probably has an internal grounding issue, possibly relating to the RCA outs themselves. Switch the amp, and I'm sure the problem will disappear.


If you find you need caps, BTW, it is because your charging system is underpowered. /story.


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## hometheaterguy

If you do not like the AVS Forum, pack up and leave. It is a science forum based on the objective, not subjective. As I cited caps help the OP's issue. The forum is not based on marketing, although companies help support the forums hosting, etc. I do not sell caps, but I know they still work and are still used. The aim of the forum is to post to help posters, not flaunt knowledge, or debate. The goal is to be understood.


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## troy_audi0

The Problem is your amp.. its doing what I would call DCing

I see this alot with Sony, Rockford & Autotec Amps

Ask a friend if you can Try his amp im 99% sure it wont happin when you plug his in..

Keep us posted..


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## pumbaa071

one question not asked it what deck he is using. if its a pioneer is probably an rca grounding problem since they are known for it. id check grounds first then go from there.


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## Steven Kephart




> Quote:
> Originally Posted by *pumbaa071* /forum/post/12282701
> 
> 
> one question not asked it what deck he is using. if its a pioneer is probably an rca grounding problem since they are known for it. id check grounds first then go from there.



Usually that causes really bad alternator whine. And it is usually internal in the head unit.


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## pumbaa071

yeah it also cause a hum or thump in subs, ive had 2 pioneers do it. you just ground the rca to the chassis and its good to go.


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## kaehn612

how do u ground the rca cables to the chassis do u just split both the red and white wires and ground both to the same place or what having the same problem just my subs make the noise only when the trucks runnin and kinda gos up n down with the idle


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