I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks

Should read 500w / 12v = 41.6 amps.

I can see I am under powered now.

On Tue, 2 Dec 2003 18:31:06 -0800, "SHRED©" wrote:

I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why are you using 325 watts? 75*4 + 250*1 is 550 watts. I know you
probably don't crank it that loud very often, but don't forget that
amplifiers are not 100% efficient. You could easily pull 50 amps with
this amplifier without turning it all the way up.

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

This is a sure sign that your amp is drawing more current than the
alternator can supply. Your electrical system has to dip into the
battery to try to supply the additional current for the bass notes,
and the current drain through the battery's internal resistance is
causing a voltage drop. That is what's causing your lights to dim.

I think it is a Napa alternator issue...as in junk.

It may be a perfectly functioning alternator, but a 60-amp model just
isn't adequate for your needs. If you constantly ask it to provide a
current that is near its limits, it will shorten the lifespan
dramatically.

I have to call them in the morning and let them know if I am going to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

I don't know how big the alternator is in a stock Civic, and 500 watts
is actually smaller than your amp, not larger.


Scott Gardner

Thanks

SHRED© wrote:
Should read 500w / 12v = 41.6 amps.

I can see I am under powered now.


550 watts damn it!!!

Couple things you might want to do.

1.) Get a higher output alternator (100-110 amps should be fine, but consider more if you have all power accessories)
2.) Not necessary but will help, get a yellow or red top battery, Acura's use small batteries
3.) Consider adding a Capcitor in the mix


"SHRED©" wrote in message news:IVbzb.26297$Bk1.22835@fed1read05...
I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks

username wrote:
Couple things you might want to do.

1.) Get a higher output alternator (100-110 amps should be fine, but
consider more if you have all power accessories)
2.) Not necessary but will help, get a yellow or red top battery,
Acura's use small batteries
3.) Consider adding a Capcitor in the mix

I am wondering if my Acura will accept a higher output Alternator?
Aren't the car's chips programmed for a certain amperage rate?
I'll ask the mechanic in the morning.

Thanks


"SHRED©" wrote in message
news:IVbzb.26297$Bk1.22835@fed1read05...
I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty,
until now.
They referred me to an auto-electric shop. This shop claims that my
car's
wiring is fine but the amplifier in my car is responsible for
destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's
and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp
and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so
with the
lights and A/C, etc..he claims the stereo is pushing it over the
edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not
blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going
to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little
of.

Why do my friends, in little Honda Civics and other vehicles, have
no
problems driving 500 watts with the stock alternators?

Thanks

Should read 500w / 12v = 41.6 amps.

I can see I am under powered now.


550 watts damn it!!!

Assuming 50% efficiency, there's your 80 amps.

I am wondering if my Acura will accept a higher output Alternator?
Aren't the car's chips programmed for a certain amperage rate?
I'll ask the mechanic in the morning.

I don't see how that can be the case.

On Wed, 03 Dec 2003 05:30:02 GMT, "Mark Zarella"
wrote:

I am wondering if my Acura will accept a higher output Alternator?
Aren't the car's chips programmed for a certain amperage rate?
I'll ask the mechanic in the morning.

I don't see how that can be the case.

Mark's right - a higher-capacity alternator doesn't force more current
into you car's electrical system, it just means that more current is
available if it's needed. Your car's computerized systems won't know
the difference, as long as the voltage is correct.

Scott Gardner

In article IVbzb.26297$Bk1.22835@fed1read05,
"SHRED©" wrote:

I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks



Class AB amplifiers are less than 50% efficient. That's where the
current is coming from, but 80A sounds high. Some of that might be
meter needle momentum.

You have a piece of crap alternator. Alternators are overloaded all the
time, it's normal. Every time you start your car, your alternator is
overloaded for at least a minute. Every time you start driving after
lengthy idling with the headlights on, the alternator overloads for a
while. Driving after getting a dead battery jumpered overloads the
alternator for about an hour.

Holding a partially discharged car battery at a perfect 14.4V would
require 100-300 hundred amps. That's not available so the alternator
has to be tolerant of being maxed-out for long periods. The only
problem you should ever have with too big of a stereo is gradual battery
discharge.

You're probably getting cheap-o alternators with poor air circulation,
undersized diodes, or bad connections to the windings. Get a better
brand and you'll be set.

1991 Acura's don't have "computerized" electrical systems either - other
than the usual engine and/or body CPU, the rest of the thing is typical
12V stuff.

Has the guy mentioned anything about overloading your battery ground
cable yet? If not, he's only seeing half the problem... hard to charge a
battery when half its connection to the vehicle is being severely
overtaxed, a standard problem in Hondas and their kin.

And, you ahve to remember that if the amp pulls 80 amps max, it does not
do that 24/7. Music has a duty cycle that's typically not much higher
than 50%, which would cut the average use in half. On top of that
however, you have to factor in lousy efficiency in the 1/3 to 2/3 power
range for a class AB amp design. But, I've seen good evidence that says
running even 1000 watt AB amps in daily drivers is sustainable on stock
electrical supply. I'd look harder at the negative battery cable first,
then at your habits - are you routinely running the battery flat with
the car off and then asking that small alternator to recharge the
battery while it also tries to run your car and your audio system?

And, your experience with car parts "lifetime warranty" alternators is
very common in my experience - except we usually saw it more with
Kragen, along with the cheesy batteries they sold. A lifetime warranty
isn;t worth the paper it's written in if you have to use it that often.
I'd find a reputable specialty shop that rebuilds alternators and
starters and pay them a little more to have it rebuilt properly next
time it tanks. It is harder to hotrod some imported alternators, but as
an example we have a shop here in San Diego that will return you a
mechanically and electrically upgraded Delco unit that is good for 140
amps in place of the 105 amp stock spec, bearings instead of bushings,
etc. - for about $150. I've run this kind of alternator in older cars
for years with good sized audio systems and had no failures.

JD

Scott Gardner wrote:

On Wed, 03 Dec 2003 05:30:02 GMT, "Mark Zarella"
wrote:



I am wondering if my Acura will accept a higher output Alternator?
Aren't the car's chips programmed for a certain amperage rate?
I'll ask the mechanic in the morning.


I don't see how that can be the case.



Mark's right - a higher-capacity alternator doesn't force more current
into you car's electrical system, it just means that more current is
available if it's needed. Your car's computerized systems won't know
the difference, as long as the voltage is correct.

Scott Gardner

I am in San Diego too and was wondering if you could help me out?

In article 2Gkzb.26355$Bk1.10516@fed1read05, "SHRED©" wrote:
I am in San Diego too and was wondering if you could help me out?


I just seen some brand new alternators on Ebay that will fit your car, seen a
130amp and 150amp for your car

The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com


"SHRED©" wrote in message
news:IVbzb.26297$Bk1.22835@fed1read05...
I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until
now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying
the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a
JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to
remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks

I couldn't agree more.


In article , "David"
wrote:
The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com

I would only correct one thing. David said the poster needs a larger
alternator "and/or" a stiffening capacitor. There's no "or" about it
- he needs a larger alternator. Whether or not he needs a stiffening
capacitor as well depends on how much larger of an alternator he gets.

Scott Gardner

On Wed, 03 Dec 2003 18:19:55 GMT, (Captain Howdy) wrote:

I couldn't agree more.


In article , "David"
wrote:
The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com

So true

In article , (Scott
Gardner) wrote:
I would only correct one thing. David said the poster needs a larger
alternator "and/or" a stiffening capacitor. There's no "or" about it
- he needs a larger alternator. Whether or not he needs a stiffening
capacitor as well depends on how much larger of an alternator he gets.

Scott Gardner

On Wed, 03 Dec 2003 18:19:55 GMT, (Captain Howdy) wrote:

I couldn't agree more.


In article , "David"
wrote:
The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com

In article ,
John Durbin wrote:

1991 Acura's don't have "computerized" electrical systems either - other
than the usual engine and/or body CPU, the rest of the thing is typical
12V stuff.

Has the guy mentioned anything about overloading your battery ground
cable yet? If not, he's only seeing half the problem... hard to charge a
battery when half its connection to the vehicle is being severely
overtaxed, a standard problem in Hondas and their kin.

And, you ahve to remember that if the amp pulls 80 amps max, it does not
do that 24/7. Music has a duty cycle that's typically not much higher
than 50%, which would cut the average use in half. On top of that
however, you have to factor in lousy efficiency in the 1/3 to 2/3 power
range for a class AB amp design. But, I've seen good evidence that says
running even 1000 watt AB amps in daily drivers is sustainable on stock
electrical supply. I'd look harder at the negative battery cable first,
then at your habits - are you routinely running the battery flat with
the car off and then asking that small alternator to recharge the
battery while it also tries to run your car and your audio system?

And, your experience with car parts "lifetime warranty" alternators is
very common in my experience - except we usually saw it more with
Kragen, along with the cheesy batteries they sold. A lifetime warranty
isn;t worth the paper it's written in if you have to use it that often.
I'd find a reputable specialty shop that rebuilds alternators and
starters and pay them a little more to have it rebuilt properly next
time it tanks. It is harder to hotrod some imported alternators, but as
an example we have a shop here in San Diego that will return you a
mechanically and electrically upgraded Delco unit that is good for 140
amps in place of the 105 amp stock spec, bearings instead of bushings,
etc. - for about $150. I've run this kind of alternator in older cars
for years with good sized audio systems and had no failures.

JD


Reminds me of the warranty on the no-name RAM at Fry's Electronics.
None of their low-end RAM works. It's junk that has been returned
dozens of times before. Sooner or later the blame shifts to you, or you
are forced to buy more expensive (high margin) RAM. Maybe you'll even
not bother to return the bad RAM. There's money to be made in selling
defective parts with lifetime warranties.

In article ,
"David" wrote:

The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com

Sorry, but a stiffening cap is worthless. Do the math for the voltage
swing on the cap and compare it to that of the battery. The capacitor
is insignificant.

You'd need to be drawing surges over 250 Amps before a cap became
worthwhile, and it would have to be a ****load bigger than a few Farads.
Effort would be better spent on adding a second battery with a very high
cranking rating.

Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.



"SHRED©" wrote in message
news:IVbzb.26297$Bk1.22835@fed1read05...
I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until
now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying
the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a
JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to
remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks

On Wed, 03 Dec 2003 23:17:43 -0800, Kevin McMurtrie
wrote:


Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.



"SHRED©" wrote in message

I would love to see "1F to 5F" of capacitance in a handheld mobile
transmitter. The ones that are used in car audio aren't the size they
are for nothing.

Scott Gardner

"Kevin McMurtrie" wrote in message
...
In article ,


Sorry, but a stiffening cap is worthless. Do the math for the voltage
swing on the cap and compare it to that of the battery. The capacitor
is insignificant.

You'd need to be drawing surges over 250 Amps before a cap became
worthwhile, and it would have to be a ****load bigger than a few Farads.
Effort would be better spent on adding a second battery with a very high
cranking rating.

Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.

what makes a cap worthless, in the car system with a lowly 12vrms the cap is
very necessary. I just want to know what you base your statement on??

In article ,
(Scott Gardner) wrote:

On Wed, 03 Dec 2003 23:17:43 -0800, Kevin McMurtrie
wrote:


Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.



"SHRED©" wrote in message

I would love to see "1F to 5F" of capacitance in a handheld mobile
transmitter. The ones that are used in car audio aren't the size they
are for nothing.

Scott Gardner


Small:
http://www.maxwell.com/ultracapacito...mall_cell.html
http://www.powerstor.com/products_supercapacitors.asp

Medium:
http://www.maxwell.com/ultracapacito...arge_cell.html

Large:
http://www.maxwell.com/ultracapacito...s/modules.html

It's a different chemistry than the giant aluminum foil caps. It's more
expensive, too. Another car battery is cheaper but you could get 416F
by putting 6 Maxwell PC2500 caps in series under your seat, if you
really wanted to. I wouldn't want to be in your car during an accident.

On Thu, 04 Dec 2003 01:13:58 -0800, Kevin McMurtrie
wrote:

In article ,
(Scott Gardner) wrote:

On Wed, 03 Dec 2003 23:17:43 -0800, Kevin McMurtrie
wrote:


Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.



"SHRED©" wrote in message

I would love to see "1F to 5F" of capacitance in a handheld mobile
transmitter. The ones that are used in car audio aren't the size they
are for nothing.

Scott Gardner


Small:
http://www.maxwell.com/ultracapacito...mall_cell.html
http://www.powerstor.com/products_supercapacitors.asp

Medium:
http://www.maxwell.com/ultracapacito...arge_cell.html

Large:
http://www.maxwell.com/ultracapacito...s/modules.html

It's a different chemistry than the giant aluminum foil caps. It's more
expensive, too. Another car battery is cheaper but you could get 416F
by putting 6 Maxwell PC2500 caps in series under your seat, if you
really wanted to. I wouldn't want to be in your car during an accident.

Thanks for the links. I think it's kind of "apples and oranges",
though, because the small and medium caps on the Maxwell site are 2.5V
and 5.0V models, and the large ones are 17 pounds and 42 pounds -
hardly what I'd call suitable for handheld mobile use. Still *very*
interesting. I had read a little about these "supercapacitors", but
had no idea they were THAT small, considering their capacitance.

Anyway, I've found capacitors very useful in several installations, as
long as you don't have unreasonable expectations of what you want them
to do. I've never heard them make bass "tighter" or "cleaner" or
anything like that. I use them specifically to take care of
flickering lights during transients, but ONLY if the alternator can
handle the average current demands, and ONLY if I've already checked
out the wiring to the headlamps to make sure it's not corroded, loose,
or undersized.

I think capacitors got a bad rep when people started using a Farad or
more of capacitance on every installation as some sort of a "bass
enhancer". That's not what they're for.

Scott Gardner

Do these handheld mobile transmitters use beltpacks to house these 1- 5 farad
capacitors lol?

Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.

I guess that you never bothered to see the voltage rating on these caps huh?


Small:
http://www.maxwell.com/ultracapacito...mall_cell.html
http://www.powerstor.com/products_supercapacitors.asp

Medium:
http://www.maxwell.com/ultracapacito...arge_cell.html

Large:
http://www.maxwell.com/ultracapacito...s/modules.html

It's a different chemistry than the giant aluminum foil caps. It's more
expensive, too. Another car battery is cheaper but you could get 416F
by putting 6 Maxwell PC2500 caps in series under your seat, if you
really wanted to. I wouldn't want to be in your car during an accident.

He's been reading too many Mark Zarella capacitor posts.


what makes a cap worthless, in the car system with a lowly 12vrms the cap is
very necessary. I just want to know what you base your statement on??

Actually, the supercapacitors he linked to would be fine for mobile
use. One of the "small" ones was 10F and weighs about a
quarter-ounce. None of them were really suitable for car use, because
they either couldn't handle the voltage, or they weighed too much, but
as long as your power requirements are less than 5.0V, there were a
lot of tiny ones that would be suitable.

Scott Gafdner

On Thu, 04 Dec 2003 18:56:55 GMT, (Captain Howdy) wrote:

Do these handheld mobile transmitters use beltpacks to house these 1- 5 farad
capacitors lol?

Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.

In article ,
"Tha Ghee" wrote:

"Kevin McMurtrie" wrote in message
...
In article ,


Sorry, but a stiffening cap is worthless. Do the math for the voltage
swing on the cap and compare it to that of the battery. The capacitor
is insignificant.

You'd need to be drawing surges over 250 Amps before a cap became
worthwhile, and it would have to be a ****load bigger than a few Farads.
Effort would be better spent on adding a second battery with a very high
cranking rating.

Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.

what makes a cap worthless, in the car system with a lowly 12vrms the cap is
very necessary. I just want to know what you base your statement on??

The car battery is very capable of holding the voltage above 12V. A
capacitor, on the other hand, stores a very small amount of power. It
takes a lot of Farads before you're doing anything significant compared
to the battery at low frequencies. One amp causes a one volt change
every one second in a one Farad cap. If you figure that bass hits last
1/4 second long, you need a lot of Farads before you're helping much.

The flickering lights that some refer to is the car's voltage bouncing
between the alternator's 14.4 volts and the battery's 12.x volts. It's
purely a cosmetic problem. Alternators are slow to adjust and a fully
charged battery barely conducts electricity above 12.7 volts. A
capacitor can help in this case by making the flicker less abrupt,
especially at engine idle when there's not much current involved.

People who find that a 1F cap is needed to stay above 12V or save their
alternator should really check their wiring. The capacitor is only
masking symptoms of another problem. As others have mentioned, ground
cables are often overlooked in inspections. Check that the battery
cables, positive and negative, are in good shape. Check that a mechanic
didn't forget to re-install ground cables after repairs. 10 guage wires
on the engine block and intake manifold are for engine control
electronics only. There are usually large ground cables at the
alternator and/or starter.

And in the original poster's case, I think he just has a crappy
alternator. They're normally indestructable.

AB can actually get into the low 60% range ... but only at full output
typically. In the 1/3 to 2/3 power range, it's a pig... more like mid 30's.

JD

Kevin McMurtrie wrote:

In article IVbzb.26297$Bk1.22835@fed1read05,
"SHRED©" wrote:



I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until now.
They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying the
Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a JL
Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to remove
the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks





Class AB amplifiers are less than 50% efficient. That's where the
current is coming from, but 80A sounds high. Some of that might be
meter needle momentum.

You have a piece of crap alternator. Alternators are overloaded all the
time, it's normal. Every time you start your car, your alternator is
overloaded for at least a minute. Every time you start driving after
lengthy idling with the headlights on, the alternator overloads for a
while. Driving after getting a dead battery jumpered overloads the
alternator for about an hour.

Holding a partially discharged car battery at a perfect 14.4V would
require 100-300 hundred amps. That's not available so the alternator
has to be tolerant of being maxed-out for long periods. The only
problem you should ever have with too big of a stereo is gradual battery
discharge.

You're probably getting cheap-o alternators with poor air circulation,
undersized diodes, or bad connections to the windings. Get a better
brand and you'll be set.

no shop, sorry - I work at the corporate offices for Directed Electronics.

JD

SHRED© wrote:

I am in San Diego too and was wondering if you could help me out?

bullcrap... personally, I ran more power than that in a 1968 Mercedes
with a stock THIRTY FIVE amp alternator without ever seeing those
symptoms. Granted, I put in a larger than stock battery and improved the
cabling throughout, but it worked fine for a couple of years before I
went with the big 140A Delco.

Rich Clark wrote a very good piece on this subject a few yeas ago,
keeping in mind this is a guy that helped start the capacitor hype... he
was running a couple of the biggest MTX class AB amps in a stock
electrical system, metered it with some expensive lab gear and the
bottom line was the car was quite stable with that much power on the
stock charging system.

JD

David wrote:

The mechanic is right!

The alternator has to provide enough amperage to power your car's entire
electrical system, charge the battery, then feed your amp. Most replacement
alternators only provide sufficient power to support the vehicle's OEM
needs, with little left for a slammin' system...

You need a larger (amperage-wise) alternator and/or a 1F (or larger!)
stiffening capacitor...

David
UnderTheDash.com


"SHRED©" wrote in message
news:IVbzb.26297$Bk1.22835@fed1read05...


I am on my 4th alternator in my 1991 Integra.
Napa autocare service centers are replacing them, under warranty, until


now.


They referred me to an auto-electric shop. This shop claims that my car's
wiring is fine but the amplifier in my car is responsible for destroying


the


Napa alternators.

I have an Alpine MRD-F752 5ch (75wx4 and 250wx1) driving 4 PA DX6's and a


JL


Audio 12".

The mechanic at the auto-elec shop claims that he tested the amp and it is
drawing between 50-80 amps!! This is a 60amp rated alternator so with the
lights and A/C, etc..he claims the stereo is pushing it over the edge.

Wait a minute...Watts divided by volts= amps.
325w / 12v = 27amps..right?

Why would that Alpine be reading so high?

Why do my headlight dim with the bass note thumps even when not blasting?

I think it is a Napa alternator issue...as in junk.

I have to call them in the morning and let them know if I am going to


remove


the amplifier. Damn I'd hate to do that it sounds so sweet.

WTF can I do? I am scrambling for electrical answers I know little of.

Why do my friends, in little Honda Civics and other vehicles, have no
problems driving 500 watts with the stock alternators?

Thanks

They make supercaps that you can hold in the palm of your hand, problem
is they are usually low voltage and expensive... so you'd be out a bunch
of bucks by the time you put enough together to use in a car audio systems.

Scott Gardner wrote:

On Wed, 03 Dec 2003 23:17:43 -0800, Kevin McMurtrie
wrote:




Even handheld mobile transmitters use capacitors of 1F to 5F. Putting a
few F on a high powered audio amp is like waxing your car to make it go
faster.




"SHRED©" wrote in message



I would love to see "1F to 5F" of capacitance in a handheld mobile
transmitter. The ones that are used in car audio aren't the size they
are for nothing.

Scott Gardner

John Durbin wrote:
no shop, sorry - I work at the corporate offices for Directed Electronics.

Turbins a desk jockey, a pencil pusher, a WHITE COLLAR MIDDLE MANAGEMENT
CLOCK-PUNCHING SCHLUB MIRED IN CORPORATE MEDIOCRITY JUST PRAYING HE
SURVIVES THE NEXT ROUND OF LAYOFFS.

But he gives me free ****...so...I really love that guy.

--
Lizard.
I mean love in the heterosexual "you're not getting my beer" kind of
way, of course.

Lizard.
I mean love in the heterosexual "you're not getting my beer" kind of
way, of course.

i'd do durbin in a heartbeat...
--
sancho
and by 'a heartbeat' i mean 'his ass'

John Durbin wrote:

Rich Clark wrote a very good piece on this subject a few yeas ago,
keeping in mind this is a guy that helped start the capacitor hype...

Richard Clark started a lot of hype. Clark and his coat-tail riding
wannabees (lovingly referred to as "clarkies") are hype-machine
extraordinaires.

I think my favorite bit of hype
was...http://www.teamrocs.com/crap/rcpunked.htm

--
Lizard

I'm not a big believer in "breaking in" speakers either, but
the post quoted below about track thirty on the Autosound test disc
might not have anything to do with break-in.
It specifically said that the tones were for "exercising
woofers before making Small/Theil parameter measurements". That's not
the same as "breaking in" woofers. T/S parameters change
significantly when the speaker is warmed up for a while, and the
parameters go right back to their original values once the speaker
cools back down.
My interpretation of the liner notes has always been that
track thirty is just for warming up speakers so you're not measuring
T/S parameters off of a cold sub.

Scott Gardner

BTW, I've heard a poster in another group that swore that whenever he
bought new home speakers, they always sounded different once he'd
played them for about a month. Then, he bought a pair of store demo
speakers that already had a few hundred hours on them. Guess what?
They sounded different after a month in his house, too. That's when
he figured that "speaker break-in" is more about our ears adapting to
the speakers than any actual change in the speakers themselves. My
experiences have been similar to his.


On Sat, 06 Dec 2003 23:41:23 -0500, thelizman
thelizman1221.yahoo@com wrote:

John Durbin wrote:

Rich Clark wrote a very good piece on this subject a few yeas ago,
keeping in mind this is a guy that helped start the capacitor hype...

Richard Clark started a lot of hype. Clark and his coat-tail riding
wannabees (lovingly referred to as "clarkies") are hype-machine
extraordinaires.

I think my favorite bit of hype
was...http://www.teamrocs.com/crap/rcpunked.htm

--
Lizard

Speaking of Richard Clark, has anyone won his "Amplifer Challenge"
yet? Or is that ten grand still sitting in his bank account? I can't
find any website that's tracking the challenge, but it's been several
years, so we should have heard about a winner, or at least heard about
how many people have unsuccessfully attempted it.

Scott Gardner

On Sat, 06 Dec 2003 23:41:23 -0500, thelizman
thelizman1221.yahoo@com wrote:

John Durbin wrote:

Rich Clark wrote a very good piece on this subject a few yeas ago,
keeping in mind this is a guy that helped start the capacitor hype...

Richard Clark started a lot of hype. Clark and his coat-tail riding
wannabees (lovingly referred to as "clarkies") are hype-machine
extraordinaires.

I think my favorite bit of hype
was...http://www.teamrocs.com/crap/rcpunked.htm

--
Lizard

ixnay on the reefay hitsay...

JD
besides, that was a long time ago... now, get away from my ass - and my beer

thelizman wrote:

John Durbin wrote:

no shop, sorry - I work at the corporate offices for Directed
Electronics.


Turbins a desk jockey, a pencil pusher, a WHITE COLLAR MIDDLE
MANAGEMENT CLOCK-PUNCHING SCHLUB MIRED IN CORPORATE MEDIOCRITY JUST
PRAYING HE SURVIVES THE NEXT ROUND OF LAYOFFS.

But he gives me free ****...so...I really love that guy.

--
Lizard.
I mean love in the heterosexual "you're not getting my beer" kind of
way, of course.

probably wouldn't last much longer than a heartbeat, from what I hear

JD
making a mental note to give Texass a w-i-i-i-d-e berth in the future...

sancho wrote:

Lizard.
I mean love in the heterosexual "you're not getting my beer" kind of
way, of course.



i'd do durbin in a heartbeat...
--
sancho
and by 'a heartbeat' i mean 'his ass'

yeah, yeah, yeah... but the guy is dead on the money on a lot of stuff,
like the debunking of the effectiveness of high ESR super caps, this
particular study I was referring to, some other good work that he's
published. The AS2000 labs do some very solid product evaluation, too.

JD

thelizman wrote:

John Durbin wrote:


Rich Clark wrote a very good piece on this subject a few yeas ago,
keeping in mind this is a guy that helped start the capacitor hype...


Richard Clark started a lot of hype. Clark and his coat-tail riding
wannabees (lovingly referred to as "clarkies") are hype-machine
extraordinaires.

I think my favorite bit of hype
was...http://www.teamrocs.com/crap/rcpunked.htm

--
Lizard