Interested in bringing the rec.audio.car FAQ up to date. I don't think
Ian Bjorhovde has updated them in over 3 years. We maintain a
searchable version online at caraudioforum.com and want to update them
to todays questions.

If interested in helping, or submitting a question you think should be
included, please stop by and add it to the FAQ: New Questions section
at: http://tinyurl.com/gqp3

To be perfectly honest, and not meaning to step on anyone's toes here, I
think the FAQ is old hat. It's clearly dated beyond belief, incomplete,
isn't particularly helpful or user friendly, and contains several
inaccuracies. It also weighs in with definitive answers on a lot of
controversial or subjective topics. I think many of the regulars here have
sort of adopted the eatel site as the unofficial RAC FAQ.

http://www.eatel.net/~amptech/elecdisc/caraudio.htm

I'd like to hear other people's takes on this.

Posted by Mark Zarella
==================
Quote of post by Lee:
Interested in bringing the rec.audio.car FAQ up to date. [...]
please stop by and add it to the FAQ: New Questions section
at: http://tinyurl.com/gqp3

To be perfectly honest, and not meaning to step on anyone's toes here, I
think the FAQ is old hat. [ ... ] I think many of the regulars here have
sort of adopted the eatel site as the unofficial RAC FAQ.
http://tinyurl.com/dwkr
==================

I agree that it is dated, that is the idea of updating it. As far as
the eatel site, it is a very good reference site, but a reference site
is what it is -- the idea of a FAQ is to reduce the volume of
information contained in a reference site to simple answers to common
questions. To give people a quick start; a way to learn the basics
quickly.
--
Lee
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Interested in bringing the rec.audio.car FAQ up to date. [...]
please stop by and add it to the FAQ: New Questions section
at: http://tinyurl.com/gqp3

To be perfectly honest, and not meaning to step on anyone's toes here, I
think the FAQ is old hat. [ ... ] I think many of the regulars here have
sort of adopted the eatel site as the unofficial RAC FAQ.
http://tinyurl.com/dwkr
==================

I agree that it is dated, that is the idea of updating it. As far as
the eatel site, it is a very good reference site, but a reference site
is what it is -- the idea of a FAQ is to reduce the volume of
information contained in a reference site to simple answers to common
questions. To give people a quick start; a way to learn the basics
quickly.

I don't see a more efficient way of learning the basics than by going step
by step through the eatel site. I do agree however that there should be a
reference in the "FAQ" format. But I don't think the FAQ is in need of a
mere update...I think it needs a complete overhaul.

Interested in bringing the rec.audio.car FAQ up to date.
[...]
please stop by and add it to the FAQ: New Questions
section at: http://tinyurl.com/gqp3

I agree that it is dated, that is the idea of updating it...

.. But I don't think the FAQ is in need of a mere update
...I think it needs a complete overhaul.

Then we'll look forward to your suggestions on how to overhaul it. What
better way to help than participate.
--
Lee
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Damn, I meant cable VS chassis

Lee wrote in message ws.com...
Interested in bringing the rec.audio.car FAQ up to date.
[...]
please stop by and add it to the FAQ: New Questions
section at: http://tinyurl.com/gqp3

I agree that it is dated, that is the idea of updating it...

.. But I don't think the FAQ is in need of a mere update
...I think it needs a complete overhaul.

Then we'll look forward to your suggestions on how to overhaul it. What
better way to help than participate.

Grounding via separate cable tied into the
battery vs. chassis grounds.

and
Gain settings, by Eddie Runner

Paul, could you include how you think it should be written?

If you find that an entry in the FAQ is incorrect, please post the FAQ
Title as well as the way it should be answered.

Thanks for your suggestion Paul.


Lee
--
Lee
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Lee,

I would suggest you might solicit some input from the various Tech
Support and Engineering dept's around the industry before you start to
pollute the existing FAQ's with what is potentially very flawed
installation or product philosophy. Most of us in the industry do not
have the luxury of enough bandwidth to write that kind of thing from
scratch just for usenet or other non-corporate projects, but I bet you
can get some proofing done that way. I suggest this because
traditionally RAC has been a veritable fount of misinformation far too
often on these kinds of things, so using un-vetted input would seem to
be much like asking the inmates of the asylum for a written business
plan detailing how to run it.

What is there in the FAQ's currently may not have been updated recently,
but it at least has the virtue of having been screened for poor content
- at some point - and has stood the test of time since.

JD
just my two cents worth on this subject

Lee wrote:

Grounding via separate cable tied into the
battery vs. chassis grounds.

and
Gain settings, by Eddie Runner



Paul, could you include how you think it should be written?

If you find that an entry in the FAQ is incorrect, please post the FAQ
Title as well as the way it should be answered.

Thanks for your suggestion Paul.


Lee
--
Lee
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Posted by John Durbin

Grounding via separate cable tied into the
battery vs. chassis grounds.

and
Gain settings, by Eddie Runner

neither one makes good sense electrically though ...

Then perhaps you can suggest an alternative answer instead of simply a
critic. Or at least clarify how it doesn't make "sense electrically" so
we can see if you have a valid point.
--
Lee
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Originally posted by John Durbin
I would suggest you might solicit some input from the
various Tech Support [...] using un-vetted input would
seem to be much like asking the inmates of the asylum
for a written business plan detailing how to run it.
What is there in the FAQ's [...] has the virtue of having
been screened for poor content - at some point - and
has stood the test of time since.

The history of the FAQ is its creation from members of rec.audio.car.
I, having been in the industry myself now for over 20 years, hope to add
to the FAQ input from same as well as the additional input from the 3500
visitors we get a day here at caraudioforum.com -- Any answers we create
or already have that appear questionable I plan on researching, which
will include running them buy Industry techs that I respect -- not to be
confused with those that I don't.

Originally posted by John Durbin
Most of us in the industry do not have the luxury of enough
bandwidth to write that kind of thing from scratch

With over 6200 posts from you in rec.audio.car in the last three years
-- averaging 43 posts per week ever week, you must not be including
yourself in this group.

I don't think we need to rewrite the thing from scratch, but it could be
improved, and making an effort to do so can't be bad. I have some
resources (a very active forum) and a bit of knowledge myself -- now all
we need are a few more people interested in helping.

Thanks for your input.
Lee


Below is John Durbin's post in its entirety:
==============================
I would suggest you might solicit some input from the various Tech
Support and Engineering dept's around the industry before you start to
pollute the existing FAQ's with what is potentially very flawed
installation or product philosophy. Most of us in the industry do not
have the luxury of enough bandwidth to write that kind of thing from
scratch just for usenet or other non-corporate projects, but I bet you
can get some proofing done that way. I suggest this because
traditionally RAC has been a veritable fount of misinformation far too
often on these kinds of things, so using un-vetted input would seem to
be much like asking the inmates of the asylum for a written business
plan detailing how to run it.

What is there in the FAQ's currently may not have been updated recently,
but it at least has the virtue of having been screened for poor
content - at some point - and has stood the test of time since.
==============================
--
Lee
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I think that may serve as a good example of what I alluded to
earlier...that is, the FAQ "taking a stand" on a somewhat
controversial issue and ignoring the other side of the story.

In the new version there are notes offering alternative, but equally
acceptable answer to some questions. I plan on adding these where
applicable. I feel that if there is more than one good answer they all
should be represented.

Yes, as long as it's factually accurate and not just "opinion".


Other instances where this is true are found ..

What would be really helpful though, is the inclusion of the actual
article as well as your suggested improvement for the official answer.

After skimming the FAQ again, I think the following improvements should be
made:

Section 1 Definitions
-- I've had several discussions in here with people regarding something
rather trivial - the term "RMS power". The "controversy", if you want to
call it that, surrounds the fact that "RMS power" is in fact a misnomer the
way it's used by manufacturers. However, it's widespread, so it should be
recognized. Therefore, I suggest that the following line be changed:

"`W' is for watts, a measurement of electrical power. One watt is equal to
one volt times one amp, or one joule of energy per second. In a DC circuit,
the power is calculated as the voltage times the current (P=V x I). In an AC
circuit, the RMS power is calculated as the RMS voltage times the RMS
current (Prms=Vrms x Irms)."

The final sentence should read: "In an AC circuit, the average power
(sometimes referred to by many manufacturers as "RMS power") is calculated
as..."

-- There's another line in this section that seems to me to be somewhat
misleading. It's as follows:

`THD' is for total harmonic distortion, and is a measure of the how much a
certain device may distort a signal. These figures are usually given as
percentages. It is believed that THD figures below approximately 0.1% are
inaudible. However, it should be realized that distortion adds, so that if a
head unit, equalizer, signal processor, crossover, amplifier and speaker are
all rated at "no greater than 0.1%THD", together, they could produce
0.6%THD, which could be noticeable in the output."

The major mistake here is the notion that harmonic distortion adds. But
this is not necessarily true. So I don't think such conclusions should be
made, nor do I think the 0.1% THD audibility phrase should be kept in. It's
not accurate. However, it should be pointed out that harmonic distortion
BELOW that number is indetectable by humans. The distinction is important
because as it stands now, it implies that 0.6% THD *is* audible, when in
fact it may very well not be. So perhaps it's not a mistake, but I think a
clarification is in order.

Section 2.10.
"The commonly accepted "formula" for determining the proper size capacitor
to use is 1F/kW (one farad per kilowatt). For example, a system running at
300W would need a 0.3F (or 300,000uF) capacitor."

This formula is bogus. There are way too many variables for this formula to
even remotely make sense. Clearly, the same rule of thumb does not hold for
a car with a 55A alternator as it does for a car with a 130A alternator.
The 1F/1kW "rule" is entirely arbitrary and quite frankly worthless.

Section 3.4
"Damping factors above 100 are generally regarded as good."

What does this mean? I regard damping factors above 10 as good. And tube
amp owners clearly regard damping factors below 10 as good. The damping
factor spec really has no basis for today's amplifiers. The best I can do
is point you towards Richard Pierce's article on the
subject...http://www.diyspeakers.net/Articles/...%20DAMPING%20F
ACTOR.pdf

Section 5.21
"These introduce distortion to the signal -- this will destroy *any*
speaker."

This line is demonstrably false. Speakers don't know what the original
signal looked like so they have no way of determining whether or not it's
distorted. The assertion that clipping tends to cause more harm than
"overpowering" is also not only counterintuitive, but flat out wrong. The
two should not be implied to be mutually exclusive, especially since section
5.22 (which is a good description) illustrates that they are not. Also, in
sections 5.21 and 5.22, the term "distortion" MUST be replaced by
"clipping". The distinction is important because upon reading these
sections people would get the impression that the distorted guitar sounds
from their favorite rock bands or the distorted quality of bootleg shows,
for instance, would be harmful to their speakers. Think I'm exaggerating?
Then you haven't been paying attention to some of the misinformation that
people spout here!

Other important additions or corrections to the FAQ should be sections on
the following topics:
-- mp3...for obvious reasons. The technology has improved and car
computers are becoming much more common. Both should be addressed.
-- The relay section should not use bosch type as the example. Those
relays are in fact not generally a good idea to use (with a few exceptions)
because often the coil resistance is lower than the resistance of the
devices they want the relay to power!
-- Hearing loss needs to be addressed. It's not brought up a whole lot,
but it is occasionally. And at the very least it should be put in because
of its importance. Not a public service announcement though.
-- Psychoacoustics is the most essential aspect of audio. It's never asked
about because most people don't know what it is. But it should be discussed
because the "correct answers" to many of the FAQ questions are based on it.

Hope this helps.

Also, if you need me to elaborate on anything I've said, or if you want me
to write anything either respond here or email me at zarellam ...at...
upstate ...dot... edu.

As I stated Lee, I am willing to proof or offer comments on someone
else's swag at covering the topic but I can't justify the time it would
take to draft it 100% either to my employer or my family. That doesn't
make me a critic, just a participant, in fact long-term participant, in
this newsgroup. I would think you of all people would take my input -
any input - as simply that and not get defensive if I didn't 100% agree
with your last post.

JD

Lee wrote:

Posted by John Durbin


Grounding via separate cable tied into the
battery vs. chassis grounds.

and
Gain settings, by Eddie Runner


neither one makes good sense electrically though ...



Then perhaps you can suggest an alternative answer instead of simply a
critic. Or at least clarify how it doesn't make "sense electrically" so
we can see if you have a valid point.
--
Lee
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Originally posted by John Durbin
As I stated Lee, I am willing to proof or offer comments on
someone else's swag at covering the topic but I can't justify
the time it would take to draft it 100%

Not getting defensive, just noting that the effort to make a single
correction to a single entry in the FAQ doesn't require much time or
effort. I would never expect anyone to rewrite the entire thing from
scratch. If you don't want to, or don't have the time to submit a
single correction or improvement, then to help, you will be left with
only the "critic's" position of either agreeing or disagreeing with
someone else's work. That's what I meant by critic, no other point in my
post. Please feel free to offer your critique of the W/RMS thread
which includes initial proposed changes for that entry.

Any help will be appreciated.


Thanks
lh
--
Lee
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Hey John:

I believe running a separate ground wire to a distro block for the
amps and head units to the battery makes more sense than grounding to
the chassis.

What do you propose is the best way to ground these devices to a
common point of return?

Rgds,
Paul

On Wed, 16 Jul 2003 03:14:34 GMT, John Durbin
wrote:

neither one makes good sense electrically though ...

JD

Paul Hanley wrote:

Damn, I meant cable VS chassis

Lee wrote in message ws.com...


Interested in bringing the rec.audio.car FAQ up to date.
[...]
please stop by and add it to the FAQ: New Questions
section at: http://tinyurl.com/gqp3


I agree that it is dated, that is the idea of updating it...


.. But I don't think the FAQ is in need of a mere update
...I think it needs a complete overhaul.


Then we'll look forward to your suggestions on how to overhaul it. What
better way to help than participate.

believe running a separate ground wire to a distro block for the
amps and head units to the battery makes more sense than grounding to
the chassis.

What do you propose is the best way to ground these devices to a
common point of return?

Rgds,
Paul

Why do you think running to the battery is better than grounding to chassis?

Les

Because I dont need to sand down the area in which I am attaching the
ground.


Well true. But you didnt answer how it makes more sense to run back to the
battery. So why is it?
I find it way more difficult to run 4 gauge back to the battery rather than
scraping a little paint away and attaching it within a couple feet.
Either way, but you spend more time and money running it back to the battery
for usually zero advantage.

Les

Originally posted by Soundfreak03
Well true. But you didnt answer how it makes more sense
to run back to the battery. So why is it?

Well, in some rare cases, due to poorly grounded body frame, old weld
points, etc; I have found that I can't get as low a ground point, under
large demand, on the body as with a dedicated ground cable run back to
the alternator casing. As I said, this is pretty rare and usually only
an issue with some of the higher powered systems.
--
Lee
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I am by no means a resource, but i try to research things alot. I think
that when you redo the FAQ, you should be brief in explination but
include links to your sources for more in-depth reading if one is not
quick to catch on.
--
sl2perfect
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