This guide will try to cover the following issues:
1-- What cable to use
2-- Power Problems
3-- Overlooked things

1: What cable to use.
So you've bought yourself a nice new amp. You now need to know what to power it with! To do this you will need to do a little bit of maths then look on the chart.

Step1 - The calculation...
Work out the RMS rating of your amp overall. eg. 2x100 RMS so you will need to work with 200watts. You will need to double this to 400watts as an average amps have 50% efficiency. So to make 200watts, it wastes 200watts (using 400 watts in total). Next you need to divide this figure by 12.6 (this is the average voltage of a fully charged battery). This will then give you the amps your amp draws.

Calculation (in general) - ((channels * RMS rating of channel) * 2) / 12.6 = amps drawn

In recap (using my example) - ((2 * 100) * 2) / 12.6 = 31.75 amps.

Step 2 - The checking...
You now need to think how much cabling you will need to run in the car in total for the amp (including ground wire). The table is in feet, so you need to work it out in feet.
Look at this table and find the draw of your amp on the top. (mine was 31.75...)

So 31 is closer to 30 so look down the 30 amp column. If you wanted to be on the safer side (better option), look down the 40 amp column. Keep going down untill you find the length of cable you needed to use (for mine i've estimated about 10ft). On the chart i stop at 11 becuase 9 is too little. Better to have more than less So at 11, a work across sideways until i get to the gauge number. In my case its 10.

That is the number thickness cabling you will need to get to work efficiently... As long as you dont run more cabling that the threshold, you shall be fine.

2: Power Problems
When your sitting in your car, letting your stereo thump away you notice that the lights keep dimming... This can be quite a common problem thats easily solved with a power capacitor. These powercaps hold up the systems voltage by charging and discharging very quickly meaning that when you hit a low powerfull note, it fills in hte voltage gap in the power feed. This means you'll get a clean voltage in times of demand.

More problems coming soon...

3: Overlooked Things
-- When uprating the power cables to run bigger amps, the most overlooked thing to uprate is the ground wire from the body of the car to the battery.

-- More coming soon...

not wanting to diss anyone.. and i know that you know your stuff luke

but in my experience.. in terms of headlight dimmage! your suposed to have 1 farad per 1000watts rms.

on my system before having a power cap the lights used to dim on big notes and there was distortion as the amps were starved of power.

after fitting power cap lights still dim.. but on the big notes the amps are given the power they need and there is no distortion... in my opinion the cap is there to give the amps what they want and not to help with dimmage. (maybe in less powerful systems)

the only real way is to upgrade battery (split charge etc) and or altenator for a high output one.

not saying your wrong!.. these are just my 10ps worth of thoughts on it! lol


Rob

To a certain extent you're right. If the lights still dim after installing a 1 farad cap, you could always get a bigger cap 2 farad for example. They dim even with a cap becuase you've used the store in the cap already.

And correct, you would get much bigger gains if uprating the battery + alternator - which is coming soon in my issues soon. Just havent got round to writing / researching properly

again these are only my views!

according to what i have read you only need 1 farad per 1000watts rms of output... using a bigger cap wont really help in excess of that.. apart from reading it.. ive tried a 2 farad cap and 5 farad..having a higher rated cap than you need will actually cause problems as it draws more current from the battery/altenator to charge itself.

the way i see it.. the altenator only has a finite output of amps it can throw out... for example in the sei here are the specs for the altenator

A/V/RPM 65/14/3500

which means.....

the alternator can produce 65 amps at 14v at 3500 rpm. so 65amps x 14 v = 910 wrms. but that is without taking into account the running of the car.. blowers lights etc

i have more than that being produced which is why i dim... ill be upgrading altenator/battery soon.. so ill post back what i find.

tis all good fun

the search for audio bliss continues lol

oh dont get me wrong, i do agree with you
Just the bigger the cap, the more that can be stored. Juat if you're drawing high at a constant rate then the cap will never recharge hence it being useless, so yea thats where uprating comes in

Can you include what an ideal alternator for an upgrade for a cinq would be, thats one thing ive never got round to thinking about or looking into.

RE: cinq alternator, either a cinq with air con from a scrappy or, if it'll fit, an alt from a bigger model.
I dont wanna pick fault with ur post Luke, it was v.informative but caps do not work, if the lights dim then uprating the big 3 can help or u can buy little caps from maplins and wire them up 2 the headlights. Caps r just a fad and a waste of money. They discharge the current but where do they recharge from?? Defeating their ow purpose.

i thought the purpose of a powercap was to store a small amount of charge that is released when the voltage drops on a big note. They recharge when the current reduces again.

Caps do other things too besides sort out dims (level/clean powersupply) so i wouldnt have said they were a total waste of money (only if you dont spend silly money on them like most charge).

However i will sort all of these issues out in the 1st post when i get the time. I think i didnt word it particularly well.

Thats what they do... but its pointless doing it, the drain on the system is constant.

A usually cheaper way to sort out power problems is a split charge system, you dont even need to use Optima batteries or anything expensive.

"The big three" Essential power upgrade for ICE

OK, so you've got your flash head unit, an amp or two (or three) powering multiple speakers and subs, but what have you done to the electrics?

One simple and (more importantly) cheap upgrade is something known as "The big three".

It involves replacing a few factory cables (3!!) with something more substantial.

1. The ground wire between the battery and the car chassis. Replace this with at least a 4awg gauge cable.

2. Change the charging wire between the battery and the alternator, again with at least a 4awg cable.

3. (Only applicable if your car has one!) Replace the alternator chassis ground cable with 4awg cable.

See, that's not too bad is it?

Doing this helps minimize voltage drops caused by high resistance in the stock cable, less voltage drop = more power for your amps!