The JBL upgrade they didn't want you to have

This contradicts what Marv told me. The component crossover to lc6 should work just fine

 

MrMarv and I just spoke about this very thing earlier this week. I wanted to add tweeters to my setup but with the LC7i, had no input for them. Talked to him about how to accomplish it. Check out this thread for a jbl amp taken apart: JBL amp disassembly?

 

Instead of modifying the amp can we just go to an 8 channel input processor? LC8 or maybe the JL Fix 86?

 

I would say yes. I am 99% positive looking at the wiring diagram the jbl amp has both mid and tweeter wires coming out separate. This is why I said that component speakers doesn't work with a jbl setup. If it wasn't the case, then there would only be one set of wires and the crossover is done like normal component speaker setup with a crossover in the door. That is not the case. So you would need a 8 input device and sum the two together. Then let the crossover from your components do the what it's suppose to do.

 

Soooo...... The component speakers won't work because the stock JBL amp runs the tweeter and midrange speaker on one cable? Mine has separate wires for all speakers. I've already seen that the non-JBL stereo is setup much different than JBL. So are you talking about non-JBL?

 

No. The jbl setup runs the tweeter and midrange on separate wires. And does the crossover in the amp. I really don't want to take away from your build. So I will bow out now.

 

I gotta say sitting on the sidelines in alot if these threads with attempts to leave the jbl amp / factory HU in place my conclusion is its all gotta go. When I upgrade my system I'm gonna gut it front to back, new HU amps etc. Will be selling the JBL setup . Just my take on this .

 

Do you have factory backup camera? If so have you found a way to retain it or do you plan to go aftermarket camera?

 

Damn that sucks. Looks like you need the lc8i. Have you left all the interior out?

 

So even after the tweeters and mid's go to crossovers that still requires 2 channels instead of 1? Really don't want to get an lc8 because I can't exchange/return it this late....

 

So this is all that I tackled yesterday. Final stage of my complete stereo upgrade. I started from the front and worked my way to the back. First I ran my 4ga power wire through the driver side grommet and pulled the excess into the cab. I added the fuse holder and used 3m double sided tape to hold it on the inside of the fender. The power cable is then ran to the KnuKoncepts Ultimate Battery Post.







Inside the cab I started to remove the whole interior and I do mean whole. The center console was easy. 2 bolts inside the storage bin unscrew and you can lift it up after you remove the shift knob. Then you unplug the 12v power accessory wire and I want to say the gear selector light plug? as well. It all lifts up then the 2nd part has 3 screws holding that in. Seats are self explanatory, front seats have 3 plugs to disconnect on each. Rear seats come out next then storage bin under the bench.




Finally the storage bins behind the seat are removed to expose the stock JBL amp and sub. Disconnect 4 plugs and unscrew the box and it's out.

I looked for a space to mount my JBL crossovers. Being that they are quite large I couldn't fit them under the center console. I've read that you want to keep them as close to the component speakers as possible so this was my solution: the front kick panels. I had to make sure they fit with all the other wires going on in there and it worked. One side is mounted higher than the other for clearance issues. I used double sided tape and RAAMmat to secure them.

 

I was really confused with all the talk of this as well. You just need that front and rear signal signal to your lc7i. That signal will go to your amp then out to your crossovers for the fronts that then split to the mid and tweet. You don't have to have the front mid and front tweeter signal to go to the signal processor because it's not like your going to use both signals.

 

I was under the assumption that the JBL amp did the crossover for the front so that you would need tweeter and front door signals for a full range signal front signal to the aftermarket amp. I'm unsure if the rear signal has been processed with either a high or low pass filter. So in my mind I was thinking to send all the signals (including sub) to the pre-amp processor to get the full range.

 

Here's could do that. The lc7i has 4 inputs. He could do the front mid and front tweeter to channel 1 and 2 then sum channel 2 to channel 1. Then the rears could go to channel 3 and the subwoofer signal would go to channel 4.

 

I only see three or six channels. I'm looking at the lc8 for the eight channels. But I'm not set on it as I'm not sure what the JBL amp is doing to the rear door signal... filtered or full range.

 

I know I said I would bow out but after thinking about it overnight I need to clarify what I am trying to say that components up front won't work. If you just take the front 6x9 wires from the jbl amp, and hook them to your crossovers to your mid 6x9's then take another pair of wires from the crossover to your tweeters, eliminating the tweeter wire, you would get no highs. But, if you take the tweeter wires in the door and hook them to the crossover to your tweeters, you will get the highs. But remember that without pulling the tweeters wires from the jbl amp the tweeters are really only running off the jbl amp and you would have double crossover.

@kenrickv, I've played with my rear speakers before and did a low pass filter on them and they went silent. Seems that the sub is pulling the lows somehow from the rear signal or the jbl amp is doing something to them internally. I will verify that and get back to you.

 

It's quite possible it may be doing it in the HU. I really haven't dug to far into that.

 

Or does the signal modification happen at the HU?[/QUOTE]

I thought the wire diagram (page 5) shows just two signals from the head unit a left and right. Presumably full range. Then maybe the two data signals from the head unit have instructions for the JBL amp on how to process.

 

I have the lc6i not 7

 

Dude, you realize there is no tweeter in the door right? And all the speakers are 6.5's. This is a 3rd gen JBL build.