If you really want to be safe, you could run 0 gauge from the front battery to the back, and use a distrubution block with a 4g output to run to the amp for a short distance, then do the same with the ground from the amp. Or, if anything, 0 to 4g reducers

Yeah, Im kinda thinking i should have done this also but I asked a lot of people on here and at local shops and they said in their installs 4 awg worked fine/ that's what they usually use or would use for a setup like mine.

If I didn't already have all the wire purchased I might redo this and just run 4 awg from the rear batt to amp and yeah used 0 from front to back, but I guess that will have to come in the future ( maybe at christmas when I plan on adding a 3rd battery the Kinetik 1400)

As a rule of thumb I use 1/0 for anything over 1000 watts. 4g should still be fine for your amp, but as mentioned resistance = heat and larger wire means less resistance.

Check your voltage at your amp, the dash gauge is normally off by a nice bit. What h/u are you using- with what voltage pre-outs? I had an older higher end Alpine h/u that only had 1v pre-outs. I had to turn my gain up most of the way to match it's output.

I would worry about keeping that amp (measure at the amp) above 12 volts, and for the sake of your equipment turned down until you get your install completed.

I think it is an older Jensen h/u but not for sure.. My friend gave me it because he got a new car that had a good stock system and so he didn't need his stereo anymore. It's at least a few years or more old and so I'm not sure what the pre-out volt is. Is there any way I can figure that out?

*** EDIT: It is a JVC Head unit, still unsure of all the goods on it thought.

Edited October 7, 201014 yr by Jd377

All the knob does is turn the gain down and up. It goes to where you have the gain on the amp set, and no higher.

Lets say your gain is 3/4 turned up. If you take your bass knob and turn it all the way up, your gain is then all the way up. If you turn it to 1/2 on the knob, then the gain on the amp is only at 1/2.

So clearly your gain, is to high.

Ok I think I found my h/u online. Here is a link to it: http://www.crutchfield.com/p_257KDG720/JVC-KD-G720.html?tp=5684

It says preamp voltage 2.5/2

I'm not sure if the numbers are different like for the speaker out and sub out? Idk but you guys can see it on the site I guess if you want to see what h/u we are dealing with. I enjoy it for a free h/u.

It could be your preout voltage. That is likely split between all of your rca's and I doubt you'd even see that total unless at max volume on HU.

I was actually surprised too when I got my Sax1200D that it wasn't very loud. I figured out though that the voltage coming from my HU preouts was extremely low. Unplugging the 2 sets of RCA's going to my other amp increased the voltage going to the sub amp by a lot.

I bought a line driver (it'll be here tomorrow) and I'll be using that to compensate for my head unit's poor preout voltage.

If you can afford it - I'd recommend an audiocontrol eqs or something similar, but if not I went with a $50 after shipping pheonix gold tld22 - got good reviews so should work fine for what I need.

I dont think that the problem. ^ You can match an amp to any HU.

I dont think that the problem. ^ You can match an amp to any HU.

Sure you can, but my problem no matter how you look at it is preout voltage. His could be too.

When I swapped in 2/0 gauge welding cable for the 4 gauge I had been running I noticed a considerable difference in sound. Go as big as you can imo.

Actually the bass knob at it's highest point only goes up to where your gain us set at on your amp. So if the gain on my amp is set to 3/4 and I turn the bass knob all the way up then the gain is still only at 3/4 because that is where I set the limit on the amp.