Assuming that I use a D-block, can I run 2 amps off of a single battery--->trunk 8 gauge run? The RMS on the 2 amps is 67.5 WPC RMS for one and 25 WPC RMS for the other. THe 25x2 will be bridged.

I am not trying to win any competitions, just have decent sound at low-moderate listening levels.

 

Bigger is better. People say they just want a little system when they start out but later on they want to upgrade. Just go with the 4G so u won't have to upgrade ur wires later. my 2 cents.

 

I should have specified: I already have the 8 gauge run for my first amp...

 

so you have an 8 gauge going from the battery to an amp, and you want to add another amp, correct?
i dont know what your amps are made for, i know that some amps need a minimum gauge wire. but i think it would be better to run atleast a 4 gauge from the battery to a d-block, and then split that to two 8 guages to each amp.

 

You will have a little less than 300 watts. Assuming less than 50% efficiency you will draw 600 watts to get the 300 watts of power. So 600 / 12.5 = 48 amps of current. You need the 4 gauge now, not later. Later you will need 2 gauge.

 

i've seen companies sell 8 gauge wiring kits that says for systems up to 800 watts, but punch's says 500 watts, so if your total amount of watts is less than 500 then go ahead and stay with 8, but i'd personally get 4awg.....

 

THe TOTAL RMS power for both amps, in the configuration I will be running will be 225. Right now, it is 100 W RMS (assuming that bridging the 25 x 2 yields 100 w in mono).

So as I understand it, 8 gauge will work but not be the most efficient, and 4 gauge would be much better. Am I correct?

 

 

Sorry, I came up with 235. If they are conservatively rated like MTX that could mean 400 watts at 12.5 volts. The actual power and rated power are seldom the same thing these days. Find out what fuse rating is recommended by the maker of the amps for the way you plan to set them up. Add the fuse ratings together for total possible long term current draw. You will need at least 16 feet of wire. 6 gauge is good for up to 35 amps of current for that wire length. 4 gauge is good for up to 65 amps of current for that wire length.

 

This is what I did. Since you already have the 8g wire running, it won't be too difficult to just swap it for a 4g.

 

Sorry, the real rating was 62.5, I messed up, so 62.5 + 62.5= 125. 125 + the 100 W in mono from amp number 2 yields 225. Either way, 225 v. 235 is not a big deal.

YOu are correct that is is prob a conservative rating. I need to look at the manuals to see the nominal current draw from the amps. That would simplify this significantly.

 

with that low of a current running, i'd stay withthe 8 gauge and runa distribution block with 2 8awg wires running out.... getting 4 awg for that low of current isn't worth the money b/c sound wise wil be barely noticable and that's not enought current to melt 8 awg wire.....

 

Well, it is enough current to cause a 1/2 volt or more drop with 8 gauge wire. 1/2 a volt could be the difference between 14.4 and 13.9. Or it could be more severe and drop you from 14.4 to 11.5. Go with 4 gauge or larger and it won't be an issue. Use 8 gauge if you want unsatisfactory sound and quality of install.