Installing Amp in 2013 Passat with Factory Fender Amplifier

Hey all,

I'm doing an amp install tomorrow, 8/5, and am trying to figure out what the best input method is going to be for the amp in my car.

Here are the specs and parts I have on hand;

Vehicle: 2013 VW Passat with Factory Fender amplifier and Subwoofer in trunk *this will be important for my question
Amp: Kicker 2019 Model CXA400.1 running at 1ohm
Sub: Rockford Fosgate Shallow Mount 8 inch running at 1ohm
Kicker LOC: Capable of 55 watts in and 8v out
Kicker High Level Inputs: basic high level inputs with RCA cables on the end

So here are the options I have because the amp can do high and low level inputs.

1. Connect the Kicker LOC before the factory amp ensuring I get the full frequency spectrum
2. Connect the Kicker LOC after the factory amplifier using the subwoofer outputs in the trunk as the inputs for the LOC.
3. Connect the High Level inputs before the factory amplifier
4. Connect the High Level Inputs to the subwoofer outputs in the trunk after the factory amplifier

I do like the range of the factory amplifier sub so it's frequency spectrum is something I am happy with if that makes a difference.

I have never dealt with a factory radio or factory amp before and am just a guy who installs his own stuff but I want to make sure I get it right so any advice would be awesome.

Thanks all!

Bryce

1 vote for option 2

Is there any reason why you feel that would be the best choice? Just looking to understand more

After doing some research on The Google on the LOC vs High Level Inputs it seems like a lot of unqualified people like myself jumping in and clouding the arguments between knowledgeable folks so it's kind of hard to pick a part the factual information from the BS ya know especially when adding the variable of using the outputs of factory amplified subwoofer outputs.

Anyways,long story short, @i am an idiot, I figure you either were an idiot when you joined back in 2006 and are a knowledgeable beast now after all these years or that is sarcasm and you knew it from the start, either way I figure you know what you are talking about so I'm headed with option 2 so thank you! If you see this and get around to an explanation for my knowledge that would be great. Thanks!

I always recommend using a line out converter, especially for the diy guy. Especially now days with the lack of repair options for factory radios and amplifiers. There is a much greater chance of grounding a speaker wire that you ran 15 feet from behind the radio to the trunk. I know in your case you will not be running it that far, but there is still many places you could run it somewhere that it may get pinched. Grounded speaker wires can take out a deck or an amplifier. If you use a line out converter with just the 6 inches of wire that came on it, a lot less chance of a grounded wire. If you pinch the rca cable, no damage other than the cable.

Oh so it didn't have anything to do with the actual properties of an LOC vs High level inputs on those subwoofer outputs?

Ok so a couple updates and I'm still using this thread because I feel it may still be relevant to the input choice I used so be patient with me.

I was impressed with the sub that I had, it was something I had previously and fit without much work in my factory vw box so I wasn't out much here. Basically I wanted more bass but the sub couldn't handle any push for extra power *or so I thought but we will come back to that...

So I got an insane deal on a JL Audio 10TW3-D4 which I have wired at 2 Ohms getting I would guess 300 watts rms based on my gain setting on my amp. Now finally I don't have to worry about distortion or anything and can just let whatever song comes on just play.

The thing that brings me back here though is that songs that I know the sub sections of well from previous installs/cars seem to be quiet in some spots of the songs on this setup and then other parts of the same songs with lower drops hit hard and sound great! It seems to be that the "higher" bass lines are quieter as if they don't go through the subwoofer as much or something but the "lower" bass lines are as expected.

I have my stereo set to 7/8 of the way up on the bass setting which should be supplying plenty of input to my LOC, I have my gain on my amp to about 7/8 as well, Low Pass Filter is at about 85, and Bass Boost I have on an adjustable remote that is about 3db out of 6db although I have increased too.

Is it possible that because I'm using the subwoofer outputs from the factory amp that they are only feeding it like say 50 hertz and down for example instead of what I'm used to sending which is like 80 or a little more so I'm not getting the opportunity to play those higher notes through my amp?

What's a possible solution?

I should mention that in the wiring schematic for audio the factory amplifier mentioned bass speakers as well as subwoofer so I know it on paper has them defined somewhat differently at least but what that means in the amplifier I don't know. I'm just a guy who likes good audio lol and I don't like it when only my rap bumps and my rock doesn't bump at all and my sweet JL sub is just sitting there

Any thoughts?

You could try setting your amp's crossover higher since the factory sub is already crossed over. It doesn't have to be as high as it goes, just set it around 200 and check for a difference.

An RTA would help pinpoint what frequencies are getting to which speakers. If you don't have one, there's an app called RTA analyzer that may work for you (haven't tried it). I'd test at a lower volume level.

If your factory sub is crossed over at a lower frequency, then perhaps you could use a processor (instead of a simple LOC) to sum inputs from other speakers as well for a broader range. Then feed that to your amp.

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My ex once told me I have a perfect face for radio.

So I would need a processor to take one input from let's say left rear bass speaker and then the other input to be the subwoofer?

Would an lc2i be a good choice? I still don't know how to give it back the filtered out signal though if I'm understanding right

If you have a summed output, that'll go to your amp, then you use the crossover built into the amp.

I should also mention I've never used one of these before either, so I can only speak in generalities.

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My ex once told me I have a perfect face for radio.

Thanks @geepherder for the help. After doing a bit of reading it seems that the LC2i will be a good choice so I ordered one on sale on amazon. Now the question is just what wires to use to feed its inputs. I posted a request in the wiring diagram section asking if anyone has one for my car to help me figure it out. I just need something that will at least give it the full bass spectrum which Im convinced the sub outputs Im currently using do not provide, Im sure they are filtered extra low.

I would use 2 PAC sni-35 and 2 y adapters to build your own summing module. Connect 1 SNI to the sub wires that you are already connected to, connect the other to the ones you are calling bass speakers. Using the 2 Y adapters connect the 2 lefts together and run to amplifier. Connect the 2 rights together and run that to amp as well. Use the gain controls on the SNIs to achieve your desired sub to mid bass level.

Radio 12V      Red/Yellow      +      Radio, 16 pin plug, pins 15, 16           
Radio Ground      Brown      -      Radio, 16 pin plug, pin 12           
Radio Ignition      (Infotainment CAN)                     
Radio Illumination      (Infotainment CAN)                     
Factory Amp Turn-on      (Infotainment CAN)                     
Left Front Speaker (+/-)      Brown/Green - Brown/Blue or Green - Brown      +,-      Radio, 8 pin plug, pins 3 - 7           
Right Front Speaker (+/-)      Brown/Red - Brown/Black or Blue - Brown      +,-      Radio, 8 pin plug, pins 2 - 6           
Left Rear Speaker (+/-)      Red/White - Brown/White or White - Brown      +,-      Radio, 8 pin plug, pins 4 - 8           
Right Rear Speaker (+/-)      Red/Violet - Brown/Violet or Yellow - Brown      +,-      Radio, 8 pin plug, pins 1 - 5           
Left Front Speaker - With Amp      Brown/Green - Brown/Blue (woofer); Blue/Black - White/Black (midrange)      +,-      Amplifier under driver seat, 38 pin plug, pins 18 - 6 (woofer); pins 13 - 14 (midrange)           
Right Front Speaker - With Amp      Brown/Red - Brown/Black (woofer); Red/Gray - Brown/Gray (midrange)      +,-      Amplifier under driver seat, 38 pin plug, pins 15 - 3 (woofer); pins 12 - 11 (midrange)           
Left Front Tweeter - With Amp      White - White/Black      +,-      Amplifier under driver seat, 38 pin plug, pins 8 - 20           
Right Front Tweeter - With Amp      Gray - Gray/Black      +,-      Amplifier under driver seat, 38 pin plug, pins 19 - 7           
Left Rear Speaker - With Amp      Red/White - Brown/White      +,-      Amplifier under driver seat, 38 pin plug, pins 9 - 21           
Right Rear Speaker - With Amp      Red/Violet - Brown/Violet      +,-      Amplifier under driver seat, 38 pin plug, pins 22 - 10           
Subwoofer - With Amp      White/Red - Brown/Red (coil 1); Gray/Red - Gray/Brown (coil 2)      +,-      Amplifier under driver seat, 38 pin plug, pins 16 - 4 (coil 1); pins 5 - 17 (coil 2)           
Aux. Audio Input Left (+/-)      Yellow - Green      +,-      Radio, 12 pin plug, pins 1 - 2           
Aux. Audio Input Right (+/-)      Gray - Green      +,-      Radio, 12 pin plug, pins 7 -

@i am an idiot, wow, thank you so much for the wiring, that is amazing and also thank you for the advice. Even though I have bought the LC2i, Im not dead set on the idea of using it so in your opinion its going to be better to use what I have installed already and just add the second set and Ys then vs using 1 bass speaker and 1 sub speaker wire and use the LC2i?

Or use the 1 you already have and put the lc2 on the bass speakers. Y adapter from both the lefts, old loc and lc2, rights together to right input of amplifier. Use the gains on lc2 to adjust sub to mid bass levels. If the original loc has gains that would be great as well.

Ok I think I understand that and I should have all the right parts coming to do it either way. One thing I discovered while trying to properly set my gain tonight was that my factory radio/amplifier does not have any bass roll off because I could crank it to 90 percent volume and the bass kept increasing with the volume at least to the untrained ear. Just an interesting tidbit. Anywho, hopefully in the next couple days I can get this installed and update the thread and let you guys know how it worked out.

Well today I fought the Vegas heat of 109 and chose to try the cheaper of the two routes first with the LC2i on hand just in case. I got another LOC hooked to the rear speakers off the factory amplifier hooked to my amplifier via Y cables and I feel like I picked up more range and could now utilize my LPF on the amp more to control sound. So now I hear it hitting more in rock music than it did before for sure but it is comparatively weaker than lower notes. I know normally these could be apples to oranges comparisons but in another vehicle I just sold I remember some of these songs hitting equally hard.

I'm starting to wonder, could this be my amp now that I have hopefully solved the range input issue? I have never used kicker brand before and never such a lightweight amp for 2 ohm, I bought it with the intention to go 1 ohm. With only 6db bass adjustment am I damned from the start?

I dunno where to head at this point because I'm dealing with two variables I have never worked with, factory stereo/amplifier and a underpowered amp.

I should mention that when I say the rock or higher notes that it can now play aren't hitting as hard as they should I feel are playing with tons of bass through the bass speakers of the factory amplified system. If I had to venture a guess, probably slightly less bass produced than by the sub. Also interesting is that with the remote bass knob probably set around 1.5db or 2db all the way to the max of 6db makes absolutely zero difference in the amount of bass produced

This may be a silly question, but can you hear any vocals coming from the sub? If so, verify the amp is set to low pass instead of high pass. I've run into this before (a passenger's shoe may have accidentally kicked a button) and the bass seemed a little weak.

If that isn't it, you can use the bass roll-off compensation (or whatever it's called) of the LC2i. Check youtube:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=video&cd=1&cad=rja&uact=8&ved=0ahUKEwju3JeJ2oXkAhXmwVkKHa5eAgsQtwIIKDAA&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D8F4Uu9lWcFU&usg=AOvVaw341QbanVzgSHtUTd1nq6_J

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My ex once told me I have a perfect face for radio.

Well you arent going to believe this. I was looking on the OfferUp classifieds last night and found a guy selling a Rockford Fosgate R500X1D for $25 in full working condition so I jumped on it. Im still working on tuning because I dont have the remote knob for it to control the bass level so its taking some work but it solved every problem and is a NIGHT and DAY difference. I have the bass on the stereo set to like 1/4 because its just too much power otherwise with Gain on the amp at maybe 1/8 a turn. Once I have the remote bass control knob that will make things so much better for controlling sound. Consider this problem solved and lesson learned again for me. Better to have too much amp and scale it back for the sub than be pushing the amp for everything its got or close to it because it starts to make the amp act erratically at least in this case. Man I have lucked out hard on the used components for this install, 150 for a JL 10TW3-D4 in a Box and 25 for a RF R500X1D and both work great! AND AND I DONT EVEN THINK THEY ARE STOLEN WHICH IS EVEN BETTER!! :)

Thanks so much guys for helping me solve the range issue and giving me the advice to get this setup installed the right way for a factory amplified stock system with an add on amp. I hope it helps someone else some day that is making the same installation decisions on their Passat or VW.