*Possible Stickies?????* Mods please read. PART 1

[Cashdollar2009]

I've noticed a few things and some questions may start to become repetitive, especially in the audio section, therefore i would like to make the proposal that we may sticky a few things such as gain settings etc... I do not take any credit for this information, it just felt that it would save the moderators some work in the future, as well as answer MANY MANY MANY questions for some car audio beginners as well as some resources for others. You can never know too much! Here they are:

Amplifier Gain Setting:

Most audio equipment dies for one simple reason. Most people push their equipment beyond its limits. Whether it is the amplifier, subwoofer or full range speakers, clipping is the number one cause of failure. To prevent clipping, use this tutorial.

To figure out what voltage you should set the gains to, multiply the RMS power of the amplifiers output by the impedance of the speaker, then find the square root of that number. If you are using an amplifier that has an RMS rating of more than your speaker(s) can handle/rated for, then use the RMS rating of the speaker (instead of the RMS of the amplifier) to determine the voltage to set your amp to. This is also referred to as gaining down.

Gain Setting Equation
Voltage of the output = sqrt(RMS Power X impedance of the speaker)
Example
Say the amp provides 100WRMS into a 4 ohm speaker:

Voltage = sqrt(100W X 4 ohms)
Voltage = sqrt(400W*ohms)
Voltage = 20V

Again, that was only an example, use the ratings of your amp to figure that out.
Setting the Gain(s)
To set the gain(s), you need two things:
1. A DMM (digital multi-meter) that is capable of measuring AC voltage (needs to be able to measure up to a range of 200V).
2. A test tone CD to use to set the gains at the correct setting.
Now, to set the gain(s):
1. Start the vehicle, and pop the test tone CD in the head unit.
2. DO NOT hook up the sub(s) or speaker(s) to the amplifier while doing this, just leave the outputs unused at this time.
3. Now, time to set up the head unit.
a. If the loudest you listen to your music at on a regular basis is 22/35 with bass @ +3 and treble @ 0 with MX (or any other sound processor) on, use those settings. NEVER turn the headunit above 3/4 of the maximum volume.
b. Remember to have the car turned on.
c. If you want to use bass boost on a sub amp, set it prior to setting the gains on the amp and use the center frequency of the bass boost (45 Hz for most amps) as your test tone.
d. Please remember that if you have a subwoofer volume control on the headunit and/or a bass knob for the amplifier, set it to the maximum before you set the gains on the sub amp.
4. Take the leads from the DMM and but them on the outputs from the amp.
5. Set the gain so that the outputs of the amplifier equal the voltage you found above. This is a MUST.
Here is JL Audio tutorial on their site:
http://www.jlaudio.c...ensitivity.html

Here is where you can download some test tones for system testing/gain setting:
http://www.ronelmm.com/tones/
http://www.eminent-t...imediatest.html

For test tones higher than 80Hz, download this program and you can create your own:
Adobe Audition Trial Version

It is best to use 50 Hz tone for a sub amp (unless you have bass boost, use the frequency that is boosted as the tone), and a 1kHz tone for a full-range amp.

This is a good way to set the gains, but if you have access to an oscilloscope, by all means use it. Then you can set the gains to their absolute maximum as you can see when the amplifier clips.

If you are wondering what exactly clipping is, and what it looks like, read this:
http://www.bcae1.com/2ltlpwr.htm

If you have any questions about this, post up, I�ll try my best to answer them.

Also, remember a sub can only handle what it can, if you set the amp to its RMS you have to remember that the sub can handle only so much. It is box dependant, but it is best if you are not experienced to follow the manufacturers recommendations.

Enjoy, and remember to thump responsibly!


Ohm's Law-Wiring:
I'm going to try to make this as simple as possible, there are only certain way woofers can be wired. You cannot wire them in anyway you choose to any ohm load you choose. There are rules to follow with Ohm's Law, which is why it's a Law and not a suggestion.

I have seen it a few times in the last 2 days, where people say they will wire them in two different way with only one being possible, and it is very annoying, and no ones seems to want to point it out.

So, I will try to make a simple list of basic woofer voice coil configurations and the only ohm loads you can wire them to. And for the noobs "Ω" is the symbol for Ohm

Single Dual 4Ω woofer: Parallel 2Ω - Series 8Ω
Single Dual 2Ω woofer: Parallel 1Ω - Series 4Ω
Single Dual 1Ω woofer: Parallel .5Ω - Series 2Ω

Two Dual 4Ω woofers: Parallel 1Ω - Parallel/Series 4Ω
Two Dual 2Ω woofers: Parallel .5Ω - Parallel/Series 2Ω
Two Dual 1Ω woofers: Parallel .25Ω - Parallel/Series 1Ω

At this point it gets to complicated to explain how they are wired so I will just post the total ohm loads.

Triple Dual 4Ω woofers: 2.67Ω
Triple Dual 2Ω woofers: 1.34Ω or 3Ω
Triple Dual 1Ω woofers: .1667Ω .6667Ω

Quad Dual 4Ω woofers: .5Ω or 2Ω or 8Ω
Quad Dual 2Ω woofers: .25Ω or 1Ω or 4Ω
Quad Dual 1Ω woofers: .5Ω or 1Ω or 2Ω

From Shizzzon:

Also, when troubleshooting, the following should be noted-

If trying to make sure you have wired your subs correctly, look below for the load range your multimeter will read in-

Before measuring resistance on your DMM, touch probes together. IF it reads 0, then you are ready to measure. If it reads something other than 0, then subtract this number from your measured reading to get the actual resistance reading.

8 ohms - 4.8-7.8 ohms
4 ohms - 2.4-3.9 ohms
2 ohms - 1.2-1.9 ohms
1 ohm - 0.6-0.9 ohms
0.5ohms- 0.35-0.45 ohms
0.25 ohms-0.17-0.22 ohms

[Ryan from Ohio]

The colors fails.

Also you have just committed copyright infringement. You must give credit to the authors and/or a link to the original information.

Quite some time ago our board almost sued another over this.

I see Aleromod doesnt have a Copyright setup below it but my board does and we do enforce it.

[a4d2a0m]

I agree... good info, but i stopped reading when it turned to blue.

[Rubiks43]

if u highlight the blue its readable.

but damn what a strain on the eyes.

[AleroDrime]

great info find u'd best cite this

[Ryan from Ohio]

www.bcae1.com

The site should be stickied.

Trouble is most people wont invest the time to read it.

it much easier to bang heads against the walls, post and then have a 2-3 page pissing contest on the basics...

[Cashdollar2009]

Sorry about the copyright infringement. I will look up all of the original sources later today. I was bored at 5 am and decided to try a few things... the ONLY reason for the different colors was so that it was ALOT easier to see the different sections just in case a mod w o split them up and put them under different stickies since they were obviouy different topics. I was just trying to save a little hassle in the future. Sorry again about the "not listing credit", i will do that soon. Just trying to help.

[WhiteV6]

Copyright infringement on what? You can't copywrite ohms law. Amp gain settings? Is that intellectual knowledge owned by someone? Paraphrase/reword if necessary.

It is one thing for someone to make a claim of "suing", and another to have a legal backing to support their claim.

[Cashdollar2009]

Originally Posted by WhiteV6

Copyright infringement on what? You can't copywrite ohms law. Amp gain settings? Is that intellectual knowledge owned by someone? Paraphrase/reword if necessary.

It is one thing for someone to make a claim of "suing", and another to have a legal backing to support their claim.

That's what i thought when i posted it, but i'd rather avoid controversy while trying to help out. I'm just going to post a link to where i originally got the posts from, although the only citing they give was that they borrow they're info from other sources so... that's about as far as i can go.

[Ryan from Ohio]

Originally Posted by WhiteV6

Copyright infringement on what? You can't copywrite ohms law. Amp gain settings? Is that intellectual knowledge owned by someone? Paraphrase/reword if necessary.

It is one thing for someone to make a claim of "suing", and another to have a legal backing to support their claim.

When you copy and paste someones literature as such it is copyright infringement.

Perry Babin spent MUCH time creating www.bcae1.com

To just drop in, copy and paste his work to another site is simply a rip off. Its jsut as easy and less controversial to simply state the subject and post the respectful link to his site.

People get VERY touchy when they spend alot of time to create something only to have someone just "take" their work.

[Ryan from Ohio]

© 1998-2008 Perry Babin All rights reserved
Site last updated: Today

www.bcae1.com

As you can see his site is Copyrighted- not that he has to technically post the copyright symbol for it to be though.

[AbHeLlRaZoR]

Oh god this reinds me too much of djforums.com... Buddy probably didn't get paid to write the articles so he isn't really loosing anything. Give the threads the credit they need problem solved. It would be different if he was distrubuting pirated music then that would be a huge issue.