Ed Explains Trippi's Hummer

[EclipseChris]

Thanks man, that means a lot that you even took time to try to help me out. Now I just need to find a translator. lol

Translation, you need a shit ton more power wire.

[woodzyspl]

Thanks man, that means a lot that you even took time to try to help me out. Now I just need to find a translator. lol

Translation, you need a shit ton more power wire.

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dammit this site needs a LIKE button..

you did what i was sorta thinking..more wire? or thicker and more wire?

i have a headake after reading that post..

[HHR Ed]

I think addressing the power delivery to the amplifiers will be a larger factor than most think. The RF amps use unregulated power supplies - less voltage IN = less current IN. Since Power is the product of voltage and current this will be a big factor, considering 11.5 VDC is 20% less than 14.4 VDC. If I were doing this upgrade, I would document the following before I changed anything:

1. The nominal voltage available with the vehicle at idle with the audio system muted

2. The minimum voltage at the B+ and B- terminals of one of the sub amps over a 10 second blast of said Bass Mekanik track

3. The average voltage at the B+ and B- terminals of the same sub amp over the same 10 second blast of the same track

4. The maximum voltage drop between the B+ terminal of the same sub amp and the output stud of any alternator during this same time frame

5. The average voltage drop between the B+ terminal of the same sub amp across the same run during this same time frame

After you've measured #1, two good DMMs (one used for measurements 2&3, the other for 4&5) like Fluke 87s or 88s can capture all of this data in a single 10 second period. It's important to document this because you want a starting point. From there, you could easily factor this data as a percentage in a number of ways.

Ideally, modifications will be made so that the amplifiers will see 14.4 VDC (when measured across the B+ and B- terminals) even at maximum output. Factoring only the subwoofer amplifiers here, and assuming each can make 3,000 watts RMS into 1 ohm (common), the math would be as follows:

3,000 x 12 = 36,000 Watts RMS

36,000 Watts RMS / 64.5% amplifier efficiency* = 55,814 Watts Input (on sine waves)

55,814 x 50% Duty Cycle (music factor) = 27,907 Watts Input (music at clipping)

27,907 / 14.4 VDC = 1,938 amps of current

That's (6) 350 Amp alternators just to feed the bass amps. If I assume the length of cable from the alternators to the amplifiers is 20 feet and assume another 3 feet from the alternators to the frame and 7 feet from the amplifiers to the frame, this gives a net length of cable of 30 feet (not including the frame rail return path, which would have very low resistance). If I pull out my copy of Automotive Wiring and Electrical Systems (Hey, I refer to it too . . . LOL), and look at the chart on page 100, I can see that 1/0 AWG (as in cable that meets the American Wire Gauge specification) is good for about 140 amps (give or take a few) at 30 feet. This will require 14 runs of 1/0 AWG cable on both the power and ground side of things just so that the sub amplifiers can play music at clipping - this does not factor all those 1,000 watt 4-channel amplifiers nor additional batteries in the rear of the vehicle that require between 7 & 10 amps each to maintain a surface charge . . . That's a bunch of ring terminals to solidly affix to the ends of cables to minimize resistance . . .

Yeah, I'm guessing there might be some "gain" in addressing this. After this was addressed, I would repeat steps 1-5 from above and factor all as a percentage. If Step 5 / Step 1 > 5%, then you still have work to do, although below 10% the law of diminishing returns will certainly be a factor . . . consider where that is currently . . .

*found at RF's web site on the 2500-1bdcp @ 1 ohm - the 2500-1 may be slightly different.

Thank you,

even if your estimates are within a 10% +/- tolerance on the power wire amperage capacity, (due to wire type and purity, exact length, and quality of connection points) I believe there is certainly room for improvement, not just in power, but in cleanliness of signal and in reliability.

And as I stated before, with greater power flow, even the mids and highs will get louder, and sound even better.

[HHR Ed]

Thanks man, that means a lot that you even took time to try to help me out. Now I just need to find a translator. lol

Translation, you need a shit ton more power wire.

lol

true

Snafu is also saying to test before and after any changes to track gains and/or losses.

Testing at the source, and at the amp, and any connection/distribution or junction point in between will reveal your week points.

[Chaise]

Wow, those 5 steps at the beginning had my head spinning, but then I understood the rest of the post... Odd, huh? Lol

Great explanation though, Snafu.

[HHR Ed]

Oh I forgot,

partial translation of Snafu's post also states that his book is an excellent source of information on automotive wiring.

[woodzyspl]

Oh I forgot,

partial translation of Snafu's post also states that his book is an excellent source of information on automotive wiring.

im looking on google now for it.

but say i would get confused real quick if i barley understand his post at all..

[hdorre]

but say i would get confused real quick if i barley understand his post at all..

Believe me, the book goes into GREAT detail. I own it, so I would know lulz

Nice job Snafu!! I can't wait for v2

[jconnway]

snafu - jesus what a response. you owned the thread just there.

[Winn]

How much and where can i get this said book????