Car Audio Forumz - The #1 Car Audio Forum - Let's make a new car audio guide

Since my creative writing skills suck. I wanted to know if anyone was interested in helping me out doing a buyer's guide/info page.

I want to make a guide that explains everything in terms people can understand that will debunk all the bad info out there. a new rec.audio.car that's much more up to date, and a good bit shorter so the newer generation who all seem to have ADD can read. Here's what I was thinking should be covered in their own sections. and a have a more technical explanation for each spec and more advanced things..but start with the basics.

head units
Amplifiers
Speakers
Subwoofers
Processors
factory integration

and a general part explaining what all the specs mean and what specs are actually important. and break that down into sectiosn
Wattage
Signal to Noise ratio
THD
Sensitivity/SPL

Rec.Audio.Ca is seriously outdated and there is way too much bad info flying around so I wanted to make a newer easier to understand guide for people.

example

Speakers: What do all the specs mean

Wattage: This specification is highly misunderstood and far too accepted as the standard for comparing speakers. The Big box stores have far too long used the wattage spec of a speaker as a marketting tool and over the years wattage ratings have simply turned into advertising numbers. What the wattage rating of a speaker actually is, is how much heat the speaker can dissipate. It has very little to do with how a speaker will sound, or how loud it can get or it's quality. It's just about heat dissipation. Peak wattage ratings are just pure advertising number with no standardization or even explanation as to how the heck they come up with that number. The real number to look for is Wrms rating, or sometimes referred to as Nominal. This is the actual rating of how much power the speaker can handle. If you want to know how loud the speakers will be, on to the next part "Sensitivity"

Sensitivity: This specification will tell you how efficient a set of speakers really are. The standard for this measurement varies and I'll explain it as we go. The general accepted standard was always the dB measurement at a distance of 1 meter from the speaker, being fed 1 watt of power or 1W/1M for short. Most speakers will fall into a range of 85-94dB's. The higher number being louder and thus more efficient. Every time you double the power fed to a speaker you gain 3 decibels of sound. So a speaker with a sensitvity rating of 85dB's would play at 88dB's with 2 watts of power, 91dB's with 4 watts of power and 94dB's with 8 watts of power. As you can see it takes a good bit of power to get a less efficient speaker as loud as a more efficient speaker which would have a rating of 93Db's. That speaker with 8 watts of power would be playing at 102dB's . As you can see this has pretty much nothing to do with it's wattage rating, other than the final loundess number. which say an 85dB speaker with a power rating of 100Wrms would still not get as loud as a speaker with an 89dB rating and 50Wrms power handling, since you need to double the power to gain 3Db's.

a Clarification on sensitvity ratings to look out for.
The standard is 1W/1M but alot of companies these days like to use the rating of 2.83v/1m
2.83v is 1 watt into an 8ohm speaker.
2.83v is 2 watts into a 4ohm speaker (standard car speaker impedance) So whatever this measurement is..subtract 3dB's to get the real number.
2.83v is 4 watts into a 2ohm speaker (JBL, Infinity and a few other companies make 2ohm car speakers) for these you would need to subtract 6dB's to get the real number. (Yes that's right infinity Kappa's will not give you 97 dB's with 1 watt of power)

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Basically like that. Solid truthful information written so that everyone can understand it. I'm going to continue writing more as I find time, feel free to comment, add your own or give suggestions/make corrections.