New Audio System for 71 Blazer

[Magnuman]

I just bought a 1971 Blazer that I am finishing up.
I brought it to a car audio place and asked what their recommendation for a system.
Here is what they recommended:
Head Unit - Pioneer DEHP6900UB
Amp - Audison LRX5.1K
Front Speakers - Hertz MLK165
Rear Speakers- Hertz HCX165
Subs- 2-10" Image Dynamics IDQ10
Audio Line Driver - Audio Control Matrix
Pre-Amp Level Controller - Peripheral PRC1

I know that this would be an incredible system, but I don't want to spend close to $4,000 on the components.

I have read reviews on the Pioneer head unit and I want to stay with it.

Can anyone propose another less expensive direction and still get decent sound quality in the Blazer?
I am willing to spend $1500 -2,000 on the components.
I also have a set of new JL Audio TR525-CX (5.25") speakers that I never used in my boat.

Any help appreciated.

 

[Hazy]

i just helped my friend choose a system for his burb. it was diamond speakers, hyfonics amps, and re subs. he was on a tight budget. but i have heard CDT speakers that will blow you away, there crossovers are huge. give you lots of options too. my focal's weren't that much. but you should go on www.woofersetc.com they have good proces and lots of brands.

btw right after i got my focal's in i heard some hertz that were amazing. but the price is hard. and if you can afford it, i would run class ab amps so you can try to avoid running caps.

here is a cheaper way that still sounds good just as an idea

alpine ida x001 (cause i like the ipod useage) item76501 289.99
cdt audio hd-62 gold item 75357 499.99
cdt audio cl-6ex item 74066 99.99
alpine pdx-4.150 item 75736 429.99
image dynamics idq10v3 item 76806 229.99
image dynamics idq10v3 item 76806 229.99
alpine mrd-m1005 item 73462 379.99

that totals 2159.93 and you could play with alot of things on there.

 

[chevyin]

i would run class ab amps so you can try to avoid running caps.

This comment makes no sense to me.

 

[Hazy]

hmm, not sure why it wouldn't. there are different class amps. alot of people i know get away with running no capacitors if they use class AB amps. but if you use something like a class D amp that is more power hungry and i guess less efficient then you need a capacitor. all depending on how much power is involved in both cases. here is a quick google search for you about the classification.

http://www.hpc.msstate.edu/mpl/education/classes/ee8223/fall00/pp91-94.pdf

any audio shop will tell you about it. nothing new, so it should make perfect sense. and if you have your own opinion about AB amps then thats fine. keep it to yourself. i was just giving my 2 cents in.

 

[Kartoon]

ive been told and read that you should never run caps because they need so much power to run, so they dont really help. that basically your supposed to get a better battery and alt and that would work and never have a cap. is that correct?

 

[chevyin]

hmm, not sure why it wouldn't. there are different class amps. alot of people i know get away with running no capacitors if they use class AB amps. but if you use something like a class D amp that is more power hungry and i guess less efficient then you need a capacitor. all depending on how much power is involved in both cases. here is a quick google search for you about the classification.

http://www.hpc.msstate.edu/mpl/education/classes/ee8223/fall00/pp91-94.pdf

any audio shop will tell you about it. nothing new, so it should make perfect sense. and if you have your own opinion about AB amps then thats fine. keep it to yourself. i was just giving my 2 cents in.

In spite of your defensive attitude, I will still reply.

I know what amplifier classes are, thanks. The problem is, you have it backwards. Class D's are more efficient than A/B's, not the other way around friend.

Furthermore, a capacitor does not create power, it merely stores it. If you buy an amp that draws too much power for your alternator to keep up with, be it due to poor efficiency, too small an alt, too large a stereo, or simply by means of personal listening habits... adding a cap to the circuit will provide NO extra power to help compensate.

So in summary, I do not see my post questioning your logic as being off base or unreasonable. You are welcome to give your 2 cents, just as I am welcome to give mine. I do not know where you get off telling me you were just giving your 2 cents, but that I should keep mine to myself. If you do not want your comments questioned, dont make them on a public message board.

Have a nice day.

 

[chevyin]

ive been told and read that you should never run caps because they need so much power to run, so they dont really help. that basically your supposed to get a better battery and alt and that would work and never have a cap. is that correct?

Generally speaking you are better off upgrading your factory wiring to accept more current flow with less resistance (called the 'big 3' wires on a vehicle charging system), upgrading the battery (if necessary)... and if those methods fail to help your power problems, upgrade the alternator. After all that is said and done, if you still want a cap, you wont need it, but you can add one if you like.

BTW, amplifiers already have 'stiffening caps' in their input stages. Seems to me if the amplifier 'required' that much more capacitance, they would have simply added it to the board directly.

 

[Kartoon]

Generally speaking you are better off upgrading your factory wiring to accept more current flow with less resistance (called the 'big 3' wires on a vehicle charging system), upgrading the battery (if necessary)... and if those methods fail to help your power problems, upgrade the alternator. After all that is said and done, if you still want a cap, you wont need it, but you can add one if you like.

BTW, amplifiers already have 'stiffening caps' in their input stages. Seems to me if the amplifier 'required' that much more capacitance, they would have simply added it to the board directly.

Im no expert but thats basically what i have read on forums that people put caps in the system but they dont actually need one, but they think they do. My boss has one on his stereo, i think just cause someone at the store told him he needed one. thanks for supporting the information for me.

 

[Hazy]

wow, to say caps aren't needed is just crazy. when you have a sub they help out alot with the big hits. of course you can do a bigger alternator and wires, but thats usually 3 times the price. if i could get a crappy cap that is like 2 farad for a 100 instead of a 400+ alternator thats just more money elsewhere. and i did have class d and ab reverse, just say that next time instead of getting into a pointless post.

 

[chevyin]

wow, to say caps aren't needed is just crazy. when you have a sub they help out alot with the big hits. of course you can do a bigger alternator and wires, but thats usually 3 times the price. if i could get a crappy cap that is like 2 farad for a 100 instead of a 400+ alternator thats just more money elsewhere. and i did have class d and ab reverse, just say that next time instead of getting into a pointless post.

How was my post pointless? You were incorrect, I corrected you.

Look into Richard Clarks write ups on capacitors, and their grossly misunderstood properties iwthin a car stereo system sometime. He is the man who originally used external capacitors in a car audio system (starting the whole craze), and even his stance is that they are merely for power conditioning (removing voltage 'ripple'), not as a power source or bandaide for an inadequate charging system.

Its still a hotly debated topic, as the use/sale of caps within the industry has become substantial, but clearly the science behind it shows the vast majority of the caps on the market today just simply have too much internal resistance (ESR) to be of any realistic use to a automotive charging system in the manner you suggest. So my stance, that they are all but pointless, is hardly 'crazy'. Your out dated stance on caps in car audio, and your aparent surprise that I would even question using one, just tells me you are not current with the topic at hand.

If you require a bigger alternator, there is no getting around that. A bank of caps wont help the alt supply any more power than it could otherwise. Any power stored in the cap, must be created by the alt.

Upgraded wiring can/will reduce resistance of power flow from the batt(s) to the amp(s), thus minimizing any 'ripple'.

If your sub amp 'required' more capacitance on its input stage, they would have added it at the factory.

Again, if you upgrade your wiring properly (like a $20 upgrade), most times you are fine. But if your alt simply is too small to meet the current demands (over time), nothing will change that besides upgrading the alt.

Buying a cap may be cheaper than buying a new power source (alt), but that doesn't make it a good decision.

 

[5280k5]

Capacitor: A capacitor is an electronic device which consists of two plates (electrically conductive material) separated by an insulator. The capacitor's value (its 'capacitance') is largely determined by the total surface area of the plates and the distance between the plates (determined by the insulator's thickness). A capacitor's value is commonly referred to in microfarads, one millionth of a farad. It is expressed in micro farads because the farad is such a large amount of capacitance that it would be impractical to use in most situations.

Schematic symbol for a capacitor

Capacity: This analogy should help you better understand capacity. In the following diagram, you can see 2 tanks (capacitors) of different diameter (different capacitance). You should readily understand that the larger tank can hold more water (if they're fill to the same level (voltage)). The larger capacitor has more area in which to store water. Just as the larger capacitor's larger plate area would be able to hold more electrons.

Capacitor and DC voltage: When a DC voltage source is applied to a capacitor there is an initial surge of current, when the voltage across the terminals of the capacitor is equal to the applied voltage, the current flow stops. When the current stops flowing from the power supply to the capacitor, the capacitor is 'charged'. If the DC source is removed from the capacitor, the capacitor will retain a voltage across its terminals (it will remain charged). The capacitor can be discharged by touching the capacitor's external leads together. When using very large capacitors (1/2 farad or more) in your car, the capacitor partially discharges into the amplifier's power supply when the voltage from the alternator or battery starts to fall. Keep in mind that the discharge is only for a fraction of a second. The capacitor can not act like a battery. It only serves to fill in what would otherwise be very small dips in the supply voltage.
Capacitors and AC voltage: Generally, if an AC voltage source is connected to a capacitor, the current will flow through the capacitor until the source is removed. There are exceptions to this situation and the A.C. current flow through any capacitor is dependent on the frequency of the applied A.C. signal and the value of the capacitor. I will go into more detail on a later page.

Capacitors from left to right: 3.3 microfarad polypropylene, adjustable trimmer cap, .0022 microfarad polyester, 20 picofarad ceramic radial capacitor, 15 picofarad ceramic axial capacitor.


ESR: ESR is the equivalent series resistance of a capacitor. An ideal capacitor would have only capacitance. As you remember, all conductors have resistance. In a capacitor, there are multiple conductors like the wire leads, the foil and the electrolyte. The resistance of all of the conductors contribute to the capacitor's series resistance. It's essentially the same as having a resistor in series with an ideal capacitor. Capacitors with relatively high ESR will have less ability to pass current from its plates to the external circuit (to the amplifiers in the case of large 1F+ capacitors in car audio). Low ESR is desirable when using a capacitor as a filter.
ESL: ESL is the equivalent series inductance of a capacitor. Since most electrolytic capacitors are basically a large coil of flat wire, it will have even more inductance than it would have if it were flat. This inductance, along with the small amount of inductance from the wire leads, will make up the ESL of the capacitor. The ESL is essentially the same as having an inductor in series with an ideal capacitor. Low ESL is desirable when using capacitors for filtering purposes.
Leakage: Even though a capacitor's plates are insulated from each other, there is a small amount of 'leakage' current between its plates. This current is generally insignificant but will cause a capacitor to slowly discharge with no external circuit path between the capacitor's leads.
Note: Some large capacitors used in car audio systems have a digital voltmeter on them. Some of these displays will have a remote turn on lead to turn on the LED display. Others will have a timer that will turn the display off after a few minutes. If, in either case, the capacitor's positive lead was removed from the power source (and the display remained on), the capacitor would be quickly discharged by the display. This is not the same as the leakage current that we previously discussed.

Film Capacitors: Many low value capacitors (less than 1 microfarad) will have a plastic type of insulator (polyethylene, polypropylene...) between the plates. Sometimes the plates are actually a metallized layer bonded onto one side of the plastic material. Multiple layers of the metalized plastic material make up the capacitor. Adding layers or increasing the size of the layers (without increasing the thickness of the layers) will increase capacitance. The following diagram is an incredibly generic film capacitor. You can see the dark blue insulating film between the cyan and violet plates. The plates are soldered to one of the terminals on one end of the plates. Half of the plates are soldered to terminal A and the other half of the plates are soldered to terminal B.

Electrolytic Capacitors: Electrolytic caps are more complex than film capacitors and are generally used for larger capacitance values (0.47 microfarad and higher). The electrolytic capacitor generally consists of 2 layers of aluminum foil with a layer of paper material between the plates. It looks a little like this:

Electrolytic Capacitor Foil: The aluminum foil that makes up the plates in the electrolytic capacitor is treated in a few different processes to make it work properly and more efficiently. The most important process is the anodizing of the foil. Anodizing is a process that forms a very thin layer of aluminum oxide on one or both sides of the foil when the foil is immersed in an acidic solution and direct current is applied to the foil (one lead of the DC power supply is connected to the foil and the other is connected to a conductive plate in the acidic solution). This layer of aluminum oxide is the dielectric (insulator) and serves to block the flow of direct current. To increase the surface area on the foil (and ultimately increase capacitance), the foil can be etched by a chemical process. This would be done before the anodizing.
Paper Element and Electrolyte: The paper element serves to hold the electrolyte in place. The electrolytic solution (generally ethylene glycol and ammonium-borate) can vary in content but must generally serve a couple of purposes. First and foremost, it must be electrically conductive to help pass the electrons from one plate to the other (the glycol part of the solution does this). Secondly it helps to heal any areas of the dielectric that become damaged (the ammonium-borate does this). If the conductive properties of the electrolyte were absent, the capacitor's value would be drastically reduced. If the healing properties were absent and the anodized coating was scratched or otherwise damaged, the capacitor would leak DC from plate to plate. The healing properties greatly increases the useful life of the capacitor.
Reverse Voltage: Electrolytic capacitors generally have a positive and a negative terminal. As we said earlier, the plates (foil) of the capacitor are anodized with a DC current. This anodizing process sets up the polarity of the plate material (it deteremines which side of the plate is positive and which is negative). We also said that part of the electrolyte was to help heal a damaged plate. Since it has the properties to heal a damaged plate, it has the ability to reanodize the plate. Since anodizing process can be reversed, the electrolyte has the ability to remove the oxide coating from the foil. This would happen if the capacitor was connected with reverse polarity. Since the electrolyte can conduct electricity, if the aluminum oxide layer is removed, the capacitor would readily pass direct current from one plate to the other (it would basically be a short circuit from one plate to the other). This would, of course, render the cap useless.
Over Voltage: All capacitors have a voltage rating. This tells you how much voltage the dielectric (insulator) can withstand before allowing DC to pass between its plates. Sometimes a capacitor has a working voltage (i.e. WVDC working voltage DC) and a surge voltage. The working voltage tells you how much voltage the capacitor can withstand long term (for the normal life of the capacitor). The surge voltage is the voltage is can withstand for short periods of time. Generally, if too much voltage is applied to a capacitor, it will fail. In electrolytic capacitors, the forming voltage (voltage used to anodize the plates) and the thickness of the paper element determine the working voltage of the cap. In film type capacitors, the insulating material (polyethylene, polypropylene...) will determine the maximum working voltage.
16 Volt Capacitors vs. 20 Volt Capacitors: As you've likely noticed, large 1 farad (and 1/2 farad) capacitors are available in both 16v and 20v versions. As was said above, the voltage rating tells you how much voltage the capacitor can withstand. It does NOT tell you how much voltage it will have when connected to your system. If both a 16v and a 20v capacitor are conected to the electrical system (with a voltage of 14.4 volts), both the 16v capacitor AND the 20v capacitor will have exactly 14.4 volts. The voltage on the capacitor will be the same as the circuit to which it's connected. In this situation, both the 16v and the 20v capacitors (which have identical capacitance ratings) will hold precisely the same amount of energy. If (IF) the capacitors were charged to their maximum working voltage, the 20v capacitor would hold more energy because it can survive higher voltage. As you can see in the diagram below, all of the electrical components have the same level of water in them (they have the same voltage). If you continue this analogy, you'll be able to imagine that the lower voltage capacitor would 'overflow' if the voltage would go too high (above 16 volts). The 20 volt capacitor could accept a higher water level (voltage) before it overflows. You can also see that when the capacitors are fully filled, the 20 volt capacitor can hold more water (energy). But... in this situation (and in a car), they hold the same amount of energy.
As a side note... The volume of water that a cylinder can hold is equal to the surface area of the cross section of the cylinder (which is analogous to the surface area of the capacitor's plates) multiplied by the height of the cylinder (which is analogous to the voltage that the capacitor's dielectric (insulator) can withstand). Increasing the surface area and/or height of the cylinder (the maximum voltage rating) will increase the maximum volume (charge) the cylinder can hold.

Overheating and Venting: An electrolytic capacitor will generally overheat if subjected to adverse conditions such as overvoltage or reverse polarity. This will cause the electrolyte to boil off which will create pressure in the sealed aluminum can that envelopes its internal components. If there were no form of controlled venting, the capacitor would eventually explode. For safety's sake, capacitor manufacturers employ some sort of pressure relief that will fracture before the capacitor's aluminum enclosure. On smaller capacitors, the vent are simply a few stamped lines in the top of the capacitor. The stamping weakens the aluminum casing slightly and allows venting when the capacitor's internal pressure reaches dangerous levels. The other type of vent (used on very large capacitors) is a plug that will blow when pressure reaches dangerous levels.

Large Capacitors (1 Farad+): Large capacitors are connected to the amplifier much the same way a battery is. This means that the capacitor's positive terminal is connected to the amplifier's positive terminal (which also means that it's connected to the battery's positive terminal). The same is true of the capacitor's negative terminal (the cap's negative terminal is connected to chassis ground with the amplifier's negative ground terminal). Like this...

Large capacitors are used as a sort of electrical shock absorber. As voltage starts to rise, the capacitor will absorb energy which will tend to keep the voltage from rising as quickly as it otherwise would. If the voltage starts to fall, the capacitor's stored energy will flow out of the capacitor to try to keep the voltage up. A capacitor's ability to absorb/release energy from/to external circuits depends on the capacitor's specs (capacitance, ESR, ESL...), the output impedance of the power source (alternator and power wire in this case) and the circuit's input impedance (into the amplifier's power supply).
Power Source with NO Capacitor: In the following diagram, you can see that the output voltage (red jagged line) of the power supply is not very steady (with respect to the white reference line). This variation may be due to some defect in the power supply or from varying current draw from other devices that might be connected to the power supply. You can see that the capacitor is NOT connected to the power supply.

Power Source with Capacitor: In the next diagram, you can see that the capacitor is connected to the power supply and the voltage is much more stable (smaller ripples). The actual amount of smoothing would depend on a lot of things like the source's output impedance, the resistance in the wire and the current draw from other devices.

Power Source with Series Resistance: The following diagram shows how series resistance (not ESR) allows the capacitor to smooth the voltage even more. The series resistance will allow the cap to smooth the voltage but would cause a voltage drop if current is drawn from the capacitor. Some low current power supplies may be designed in this way to provide a very smooth output voltage. This will generally only work well if the current draw is constant and known when designing the power supply.

Large Caps and Car Amplifiers: The following diagram shows how the voltage could drop if the alternator's regulator couldn't react quickly enough to prevent a voltage drop. You should notice that the capacitor is not connected. The white line is the alternator's regulated voltage (approximately 13.8 volts). The dips are where the current draw is high. The deeper dips are points where the current draw is even higher.

The diagram below shows what a large capacitor is supposed_to_do for a car audio system. You can see how the ripple is reduced now that the capacitor is connected. The dips in voltage are smaller. If the capacitor does its job, the added voltage (less voltage drop means higher voltage available to the amplifier) would give you more power output, especially with amps with unregulated power supplies. You probably noticed that I said 'supposed_to_do' earlier. This is because there has been some discussion as to whether a capacitor is a help or a hinderence when it comes to keeping the voltage at a higher level than without it. Of course, if you ask someone that's spent more than $100 on a capacitor if it helped, they'll tell you that it has. Why on earth would someone 'fess up' to wasting that much money on 'snake oil'. I've yet to see a capacitor make an audible difference.

NOTE: For maximum benefit, you should keep the length of wire between the capacitor and the amplifier to a minimum. Anything (wire, distribution blocks, fuses...) between the capacitor and the amplifier will reduce the capacitor's ability to quickly supply the current needed by the amplifier. Of course, if you have multiple amplifiers and want the capacitor to benefit all of them, you'll have to connect it to the distribution block. TECH TIP:
Charging large capacitors: When connecting a large capacitor (1/2 farad or larger) to the 12 volt source, you may want to charge it slowly before making the final connection to the power wire. Most capacitors come with a resistor to charge the cap slowly. If you're working on your system, and disconnect the capacitor, the cap may get discharged (something might accidentally touch across the terminals or it may partially self discharge over time). If you can't find the original resistor to recharge the cap, you can recharge it with a standard test light (you know, the one with a light bulb, not one of those fancy pants test lights with LED indicators). There's a somewhat helpful demo near the bottom of the page.
If you don't have a test light and want to use a resistor to charge or discharge your capacitor, use a ceramic encapsulated high power resistor like the one below (I'd recommend using a resistor rated for 10 watts or more and about 20 ohms). If you use a small resistor (i.e. a 1/4 or 1/2 watt) of too low value (less than 100 ohms), it may get hot enough to seriously burn your fingers.

Ruler values are in inches.
REASON: The reason you may want to charge a cap slowly is to reduce the arcing involved with fast charging. This arcing won't hurt the cap but it might damage the chrome or gold finish on the connectors.
This demo shows how the test light brightness indicates the charge level in the capacitor. Put your cursor over each capacitor charge status and watch the brightness of the test light. If you have a slow connection, it may take a second or two for each image to load. Click on the amplifier below and the image's position will be optimized. [SIZE=-1]Charge Status
Completely DIScharged | Half Charged | Completely CHARGED | Finished

Discharging the Capacitor: If you're going to remove your capacitor for some reason, you may want to completely discharge the capacitor to prevent creating a hazardous situation. To discharge the capacitor (after it's disconnected from the system), simply provide a path for the current to flow from one terminal to the other. You can use either the test light or the resistor. After it is discharged, you may want to connect the terminals together with a piece of wire or resistor. Some large capacitors will act like a battery and develop some small voltage across its terminals. Since the capacitor is likely a large capacitor (over 1/2 farad), the small voltage could be dangerous. Even if your capacitor's design doesn't cause it to develop a significant voltage when not in use, leaving the terminals connected will leave no doubt whether the cap is charged or not.
Charging with a Resistor: If you need to know how long it will take to charge a capacitor with a given resistor, you can use the following calculator. The output data tells you how long 'one time constant' is (time to reach 63.2% of the difference in voltage between the capacitor's voltage and the supply voltage). It also tells you how much time it will take the capacitor to become charged. Lastly, it tells you the maximum power dissipation across the resistor (use this value as a guide in selecting a resistor).
[/SIZE]


Input Power Supply Voltage? Volts Capacitor Value? Farads Resistor Value? Ohms Output One Time Constant? Seconds Total Charging Time? Seconds Maximum Power Dissipation? Watts
Time Constant: A capacitor's time constant is the time it takes for the capacitor to charge to 63.2% of the supply voltage when charged through a given resistor. At the end of one time constant, if the supply voltage is 10 volts, the capacitor will have charged to 6.32 volts. A capacitor is condidered to be fully charged after 5 time constants. After 5 time constants, the capacitor will have charged to 99.2% of the supply voltage. The following chart shows the charging curve for a 1 farad capacitor and a 50 ohm resistor. As you can see, the capacitor charges more quickly at first and then (as the difference between the capacitor's voltage and the supply's voltage is reduced) the rate of charge slows. As the capacitor reaches full charge, the current flow is reduced to nothing.

Time Constant Calculations: The formula for 1 time constant is T=RC where T=time in seconds, R=resistance in ohms and C=capacitance in farads.
For a 1 farad capacitor and a 50 ohm resistor... T=RC T=50*1 T=50 seconds
This means that the voltage across the capacitor will be at 63% of supply voltage (8.72 volts for a 13.8 volt supply) after 50 seconds. Earlier, I said that the time constant is the time to charge 63.2% of the difference in voltage between the capacitor's voltage and the supply voltage. After one time constant the voltage across the cap was 63% of the supply voltage. This means that the voltage across the charging resistor is now only 37% of the supply voltage (instead of 100% of the supply voltage when the capacitor was fully discharged). This will reduce the current flow through the resistor into and into the capacitor. For the second time constant, the capacitor's voltage will increase only 63% of the voltage across the resistor. (13.8-8.72=5.08 volts).
For the second time constant... 13.8-8.72 = 5.08 volts (voltage across resistor at beginning of second time constant) 5.08*.632 = 3.21 volts (63% of the voltage across the resistor)
At the end of the second time constant, the voltage is going to be the voltage at the end of the first TC plus the voltage increase from the second TC. In this case, it was 8.72 volts + 3.21 volts or 11.93 volts. If you look at the chart above you can see that the charging curve crosses the 11.93 volt mark at 100 seconds (2 time constants).
Calculating Voltage at any Given Time: If you want to know the voltage at any given point in time, we can use the following formula. We'll use 65 seconds in this example.
Vc = Vsupply(1-2.718-t/(RC)) Vc = 13.8(1-2.718-65/(50*1)) Vc = 10.04 volts
At 125 seconds... Vc = Vsupply(1-2.718-t/(RC)) Vc = 13.8(1-2.718-125/(50*1)) Vc = 12.67 volts
Input Power Supply Voltage? Volts Capacitor Value? Farads Resistor Value? Ohms Total Charging Time? Seconds Output One Time Constant? Seconds Instantaneous Capacitor Voltage? Volts

 

[5280k5]

There's some other good info here too:
http://www.bcae1.com/charging.htm
http://www.bcae1.com/chargin2.htm
http://www.betteraudio.com/geolemon/newmain/battcapalt

 

[chevyin]

There's some other good info here too:
http://www.bcae1.com/charging.htm
http://www.bcae1.com/chargin2.htm
http://www.betteraudio.com/geolemon/newmain/battcapalt

Geo and I have discussed his prioritization of adding a cap before upgrading the alt. I believe he has since agreed he placed to much emphasis on caps when he wrote that (the last link).

Again as I said before, if you need an alt, you need an alt. Adding a cap wont solve a lack of power supply, therefore adding a cap before upgrading the alt makes little sense.

And once you've upgraded the alt (presuming it needed it, if not, then dont) and the big 3, and you have a good condition battery, you will find you have no light dimming, nor would adding a cap make any audible difference in your stereo. If you want a cap just for the looks, go ahead. But no evidence Ive read has proven adding a cap will make any realistic difference in stereo performance.

edit: nice thorough post 5280K5

 

[Hazy]

im still going with a cap before an alt because of price. it helps with the dimming lights on the subs big hits. thats just plain and simple. i would love to do a new alt, but i don't want to spend the money so a cap works for me. not trying to improve my sound with it, just other things.

 

[chevyin]

im still going with a cap before an alt because of price. it helps with the dimming lights on the subs big hits. thats just plain and simple. i would love to do a new alt, but i don't want to spend the money so a cap works for me. not trying to improve my sound with it, just other things.

If you want to improve dimming headlights, put the cap on your headlight circuit. Buying one for your audio system is money wasted.

This is pretty simple guys, you either have a big enough power supply (alt), or you do not. Adding caps will not change that. And if that's not the problem, simple resistance in the circuit is. Dimming headlights is a symptom of low voltage. Upgrading your factory wiring would make as much, if not more difference, than a cap. And its a considerably cheaper upgrade than a cap. If we are keeping track of cost here.

But in the end, its not about price here is it? Its about fixing a problem. If I could recommend buying a $.50 part to fix the problem, I would. I have no profit to be gained here, Im just trying to keep you from spendind cash on something that is most likely not going to give you the results you want/need.

Im not sure what other problems you would expect adding a cap to your stereo circuit would solve.

 

[Hazy]

well i see where you are going about fixing the circuit that has the problem, but if the lights are dimming to the bass. and by adding a cap in series with the amp it will take the current from the stored voltage in the cap and not anywhere else in the system. so adding a cap is perfectly fine, i guess thats why audio shops do it all the time. hmm

 

[chevyin]

well i see where you are going about fixing the circuit that has the problem, but if the lights are dimming to the bass. and by adding a cap in series with the amp it will take the current from the stored voltage in the cap and not anywhere else in the system. so adding a cap is perfectly fine, i guess thats why audio shops do it all the time. hmm

Ive explained this to you already, I guess I need to again.

Increasing the size of your factory wiring (the big 3) will reduce resistance in your stereo circuit, thereby reducing the voltage drop occurring when the bass hits.

You say the system will take power from the cap and nowhere else, that's simply not true nor do you seem to understand how an electrical circuit works. The cap's storage capacity will be dependant on system voltage. If you do not upgrade wiring and have excessive voltage drop in your power/ground cables, the cap will experience the exact same voltage loss as the rest of the circuit. Basic electronics there.

A cap is nothing more than a storage device, like a battery. Unlike a battery, it has a faster charge/discharge rate. This is what people love about caps, not realizing the ESR of their cap severly limits that very effect. Why do you think amplifier designers use an array of small caps in their power input stage, rather than one giant cap? ESR. Look it up, Im tired of explaining this same point to you.

Local shops add caps all the time, hence they MUST be useful... is that your arguement here? Well heck, lots of local shops also install Pyramid or Boss equipment, must be good stuff too. Go to a local shop that sells batts but not alts and what do you suppose THEY would say you need? Must be true too, right? Ive already addressed the fact that caps are so entrenched in the indutry due to sales figures. But again, that does not prove they are useful. It only proves they will try to sell us anything they can, and if marketed properly, we'll obviously buy it. Whether we truely need it, or not. Even when people explain why you dont need it, the marketing and rumors about caps have you convinced it will solve all your charging system problems. Good luck with that.

Again, even Richard Clark, the very man who first used a 'stiffening cap' in car audio disagrees with your assessment of their use, and their portential benefits to your audio system. Look it up, RC is highly volcal about how the industry has twisted his invention just to turn a profit.

Dont be a lemming, think for yourself. Research the topic abit. On page 1 you were trying to inform me you only need a cap when running class D amps. You then changed it to class A/B's, citing a typo. Either way shows your shallow knowledge of the topic. Not trying to be an ass, but clearly you are not very well versed on the topic, I do not understand why you seem to think you are at this point. Deciding if a cap is necessay based on your amplifier topology? Makes zero sense.

BTW I can provide graphs of tested amplifier topologies that shows the basic efficiency differences between D's and A/B's is insignificant at maximum output levels. The class D's are only substantially more efficient when running at low to moderate levels. After that, the A/B's efficinecy increases to nearly that of a class D. Again, fairly common knowledge in the industry today, that you dont seem to even realize.

Also on page 1 you were amazed someone would even question using a cap. Again, shows you are not well versed on this topic. This arguement has been raging almost ever since Mr Clark showed off his stiffening cap idea so many years ago. You were not even aware this debate exists, and yet now you seem to feel 100% confident you know the whole story. Hmmm

Believe what you want. Ive tried to inform you, if you wont listen, at least I tried. Throw good money after bad and go buy a cap if you want. *shrug* Heck, that pimple faced kid working for minimum wage at the local car audio shop says you need it, so obviously you do!

Have a nice day.

 

[Hazy]

i don't need your graphs or your long replys, my truck is proof enough that a cap does the job. my lights don't dim anymore. like i said before, i would love to upgrade the alt. but thats simply 3 times the cost. i don't think it is right for you to say it doesn't work. works over here, and at alot of other places.

this is getting tiring. im going to unsubscribe so i don't have to read this crap in my email every day.

 

[chevyin]

i don't need your graphs or your long replys, my truck is proof enough that a cap does the job. my lights don't dim anymore. like i said before, i would love to upgrade the alt. but thats simply 3 times the cost. i don't think it is right for you to say it doesn't work. works over here, and at alot of other places.

this is getting tiring. im going to unsubscribe so i don't have to read this crap in my email every day.

*sigh*

Im glad the cap worked for you. Unfortunately, replacing like $20 worth of wire would likely have done the same thing, only better. And, for your information, over my many years in car audio, Ive seen plenty of lights stop dimming when a cap was added too. Im not a beginner to this topic, as you seem to think. Witnessing light dimming stop, with my own eyes, does not make me blind to the facts behind why it occurred.

In either event, as I said before, buy a cap, no skin off my back. But I will continue to educate people on them, if asked here. You dont have to agree with me, Im sure I can learn to live with that.

Have a nice holiday season.

 

[Randy92782]

I have to agree with chevyin here. My brother has a capacitor and i honestly think they are kinda pointless. I've never owned a capacitor or will i. As long as they make bigger wire and more amperage alternators that's the way i'm going regardless of price. It's just safer to me. I'd hate to find i melted a few wires cause i thought a capacitor stored enough to not have to worry about it