# LC7i - 3rd Channel Input Question



## Theguy6792 (Jun 8, 2017)

Installing a LC7i in my 2014 Elantra this week, and ditching the LC2i I currently have hooked up. I lost a bunch of factory sounds (menu beeps, nav voice, and phone call sound) and fader control with the LC2i because I tapped the rear speakers coming from the factory amp and have aftermarket components up front running to an Alpine amp (signal from LC2i). Basically got a LC7i to fix that by being able to use most/all of the speaker outputs from my factory amp.

My question is which speakers should go to which channel? Basically from my factory amp I have 3 sets of speaker outputs (front tweeters/woofers and rear door speakers). I am thinking front door woofers to CH1, front tweeters to CH2, and rear speakers to CH3? Or should I do front woofers to CH1 and the rears to CH2 utilizing the "AutoSum" feature the LC7 has? OR is there another configuration you guys would recommend?

Thanks in advance folks.


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## FordEscape (Nov 23, 2014)

So this is your OEM system (see Search Wiring Diagrams for '13 Elantra since '14 isn't available) ?










Please explain in more detail exactly where you are trying to go in terms of 'new' amps and speakers ....

*1. IF your new front components are passive XO tweeter/woofer pairs, then I'd do this:*

OEM front > LC7 "main" + OEM tweeter > LC7 ch2 *[Sum "main" + ch2 in LC7]* > new amp ch1/2 > Front passive XO component speakers

OEM rear > LC7 ch3 > new amp ch3/4 > Rear speakers

^this will allow use of OEM fader since F&R are on discrete channels

*2. IF your new front components are 'active' using the XO in the new amp, AND you have 6 channels of new amp available:*

OEM front door > LC7 "main" > new amp ch1/2 > front woofers

OEM tweeter > LC7 ch2 > new amp ch3/4 > front tweeters

OEM rear > LC7 ch3 > new amp ch5/6 > Rear speakers

^this will allow use of OEM fader since F&R are on discrete channels, _but all XO will be per OEM amp XO since that is just 'passed through'_ - set the new amp XO to 'defeat' lest you suffer problems due to 'stacked' XO
*3. IF your new front components are 'active' using the XO in the new amp, BUT you only have one 4-channel new amp:*

OEM front door > LC7 "main" > new amp ch1/2 > front woofers

OEM tweeter > LC7 ch2 > new amp ch3/4 > front tweeters

OEM rear > OEM rear speakers (bypass LC7 - leave rear 'as OEM')

^this will allow use of OEM fader since F&R are on discrete channels, _but all XO will be per OEM amp XO since that is just 'passed through'_ - set the new amp XO to 'defeat' lest you suffer problems due to 'stacked' XO


IF you want to 'shift' the front active component XO from the OEM amp to the new amp so you have total control of the front active XO, you'll need to sum the front and tweeter in LC7 for options 2&3, then you can do the active XO in your new amp.

IF you sum OEM front and rear in the LC7, then you lose the OEM fader control under any scenario (and in fact if you set the fader anywhere other than 'null' in that case then things will likely get weird on the output side). I can't see any reason to _ever_ 'sum' OEM front and rear in your case since front door+tweeter will give you 'full range' for your new front components.

Follow that?


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## Theguy6792 (Jun 8, 2017)

Sorry I didn't realize I left out so much info. Let me explain better.

My current setup consists of the following:
Factory Nav Headunit
Infinity Reference 6030cs Components (Front)
Stock 6.5" (Rear Doors)
Alpine MRP-M500
Alpine MRP-F300
Alpine Type-E 10" Sub
LC2i

So the LC2i is grabbing signal from my rear speakers, which are still connected to the OEM amplifier in the trunk. The amplifier is no longer feeding signal to the front speakers, as I have disconnected the wire. I used the existing OEM wiring instead to run to my Alpine 4-Channel. Currently only running the front speakers off of the Alpine, but will be running new rears as well shortly.

The MAIN output of my LC2i is feeding the Alpine 4 Channel, while the Sub output is feeding my mono block.

Basically I will be installing the LC7i, as well as a new set of 6.5" coaxial in the rear. The front AND rear speakers will now be fed to my Alpine 4 Channel, leaving all of the OEM speaker outputs disconnected from my OEM amp. I was wondering from here, how would I utilize those OEM speaker outputs for my LC7i? Where to feed the OEM tweeter, woofer, and rear wires on the unit.

Here is a link to my car's factory setup. If you scroll down a bit to the "External Amplifier", you will see the OEM amp I am discussing. I am using the outputs from "Connector E"

Hyundai Elantra: AVN Head Unit. Components and Components Location - AVN System - Body Electrical System - Hyundai Elantra MD 2010-2017 Service manual


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## FordEscape (Nov 23, 2014)

OK, that info helps and your proposition is 'sporting' if you want to keep the OEM fader control between F&R since the summing combinations in the LC7 are limited/defined.

To keep the fader you don't want to 'sum' OEM F & R in the LC7. That means you must use all 3 LC7 input ch for front & rear (1 ch in for front tweeter, 1 in for front door, I ch in for rear) and you use two ch out for front and rear on the MRP-F300 as follows:

OEM front out > LC7 "main in" + OEM tweeter out > LC7 ch2 in [Sum "main" + ch2 ONLY in LC7] > LV7 "main" out > MRP-F300 ch1/2 > Front 6030cs passive XO speakers (note you must to this to get full-range front input for your setup)
OEM rear out > LC7 ch3 in > LC7 ch3 out > MRP-F300 ch3/4 > stock rear speaker
^this will allow use of OEM fader since F&R are on discrete channels; You're using the LC7 to sum the two front OEM amp outputs since there's no provision for 'summing' using the speaker level inputs on the MRP-F300.
With ^that^ you don't have any more LC7 out to use for the sub 

HOWEVER, the MRP-M500 allows speaker level inputs, so you can "jumper" from either the LC7 "main input" OR the LC7 ch3 input > MRP-M500 speaker level input.

You're effectively using a "WYE" to split either your OEM front door or OEM rear output to drive your sub. The difference between those choices will depend on which OEM output gives you the volume/fader control at your sub you find most 'workable'. Remember, lacking a dedicated OEM sub output, whatever you do your sub will be subject to the volume/fader control affecting the chosen OEM source speaker.

*IF, you are willing to sacrifice HU fader control F-to-Rear in favor of more control of the sub ....*

OEM front out > LC7 "main in" + OEM tweeter out > LC7 ch2 in [Sum "main" + ch2 ONLY in LC7]. This gets a full-range signal for your front and rear speakers.
Using an RCA WYE, one side ... LV7 "main" out > MRP-F300 ch1/2 > Front 6030cs 
Using an RCA WYE, the other side ... LC7 "main out" out > MRP-F300 3/4 > Rear Stock Speakers (
 the need for the WYE on LC7 main out because LC7 can't sum both "main in" and ch2 in to "main out" AND ch2 out; all summing goes to "main out" only  ). The MRP-F300 aparrently can't split two-channel input to four channel output . Your LC7 ch2 out will have only the OEM tweeter level signal so you can't use that alone for your rear full-range speakers  (so LC7 ch2 out will not be used).
OEM rear out > LC7 ch3 in > LC7 ch3 out > MRP-M500 ch3/4 > sub
^this will 'fix' the front/rear relative level based on how you set the MRP-F300 ch 1/2 and 3/4 gains
^the sub level will be set by LC7 ch3 level controls, you can use accubass on that channel, AND the OEM HU 'fader' will change the sub output relative to all the other speakers (because what the HU _'thinks'_ is rear speakers is _actually_ the sub).
I'd be inclined to try this since the level of the sub against everything else is more important to me than the level of F & R relative to each other (I tend to want the rear to always be low relative to front, as if mimicking 'rear ambient fill' and keeping the front stage 'prominent') 

AFAIK none of the LC?i options will provide discrete front, rear and sub level controls at the HU for your situation - lacking a discrete OEM sub output.

Follow that?


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## Theguy6792 (Jun 8, 2017)

FordEscape said:


> OK, that info helps and your proposition is 'sporting' if you want to keep the OEM fader control between F&R since the summing combinations in the LC7 are limited/defined.
> 
> To keep the fader you don't want to 'sum' OEM F & R in the LC7. That means you must use all 3 LC7 input ch for front & rear (1 ch in for front tweeter, 1 in for front door, I ch in for rear) and you use two ch out for front and rear on the MRP-F300 as follows:
> 
> ...



Yes, that explains it very well actually.

In all honesty, I don't mind losing the F/R fader all that much. I wanted to retain as many factory features as possible, but I am much more concerned about the factory sounds rather than fader. The Bluetooth calls and Nav voice are much more important to me as I tend to leave fader in the middle anyway. Just wanted to see if I could retain it. Turns out all of those factory sounds are link to the front speakers which is why I went with the LC7i, so that I could just use all speaker inputs.

So just to clarify. I would have my wiring as follows:
- Front Woofers --> CH1 LC7i
- Front Tweeters --> CH2 LC7i
- Rear Speakers --> CH3 LC7i

- Sum CH1 & CH2 for LC7i
- Use "Main" RCA out for front components on F300
- Use CH2 RCA out for rear coaxials on F300
- Use CH3 SUB RCA for subwoofer on M500

If I SUM CH1 & CH2 together, wouldn't CH2 output become useless only allowing me to use the MAIN and SUB outputs? Or am I misunderstanding the LC7i instruction manual? If that's the case I will just have to use a couple of Y splitters for my 4 channel.


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## FordEscape (Nov 23, 2014)

Theguy6792 said:


> .....If I SUM CH1 & CH2 together, wouldn't CH2 output become useless only allowing me to use the MAIN and SUB outputs? Or am I misunderstanding the LC7i instruction manual? If that's the case I will just have to use a couple of Y splitters for my 4 channel.


*YES, good catch*, I didn't realize that and edit my post 'till while you were replying!

So, the corrected short form:

- Front Woofers --> CH1 LC7i
- Front Tweeters --> CH2 LC7i
- Rear Speakers --> CH3 LC7i

- Sum CH1 & CH2 for LC7i
- Use "Main" RCA WYE out for front components and rear speakers on F300
- Use CH3 SUB RCA for subwoofer on M500


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## USS Enterprise (May 26, 2007)

Just a thought, the front channels should be full range. If so, then why not just run the front channels into the LC2i and call it a day? (instead of the back channels)
If fader isn't all that important, I mean.

My wife was set up like this in her Genesis when she had an lc2i, and still is into an ms-8.

Bluetooth, everything all perfect.

My sonata, same thing. Front channels into the lc2i or ms-8 worked perfect.

Would save you money, plus simplify the setup considerably.

And if you REALLY wanted the fader, it could be figured out. (I dunno, maybe an Lpad for the rears?)


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## FordEscape (Nov 23, 2014)

USS Enterprise said:


> Just a thought, the front channels should be full range. If so, then why not just run the front channels into the LC2i and call it a day? (instead of the back channels)
> If fader isn't all that important, I mean.
> ....


Back to the problem in *his case *of needing to get _all 6_ F & R outputs to capture all the vehicle tones due to how they are distributed in the Elantra. LC2 has no provisions for summing multiple inputs.

On my Escape for example .... I must input front+rear to my MS-8 to capture the backup alarm tones that are on rear channel HU outputs only (all other vehicle tones and voices are on the front).

IF his front indeed has all vehicle tones and voices, cool, but still the LC2 can't sum front tweeter and front doors to get full range from his *4-ch front*.

In your case, apparently all the vehicle voices and tones are on the *2* L&R front channels since using those _only_ let everything work just fine with a non-summing LC2i.

Lot's of vehicle variations to keep track of


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## Theguy6792 (Jun 8, 2017)

USS Enterprise said:


> Just a thought, the front channels should be full range. If so, then why not just run the front channels into the LC2i and call it a day? (instead of the back channels)
> If fader isn't all that important, I mean.
> 
> My wife was set up like this in her Genesis when she had an lc2i, and still is into an ms-8.
> ...


Just as FordEscape said, I am looking to utilize every signal coming from my factory amp. I originally had the front signal for my LC2i, which in that case everything worked fine as I have stock rear speakers. However once I upgrade the speakers and amplify them on my Alpine, the factory rear signal would be nonexistent. I would have lost other (minor) features. Such as when the Nav voice kicks in, the music fades to the rear at a lower volume. If I had no rear signal after upgrading my speakers the audio would just cut out completely.

Also another factor was that I found a LC7i at a STUPIDLY cheap price (lower than I paid for my LC2i), and was able to sell my LC2i for almost $35 more than I paid for it (out of country buyer). So I basically went for it. I lost nothing but gained a few bucks and a better unit.

I could have easily just used Y-Splitters on the LC2 but like stated it wouldn't sum the signals for full range. I am just trying to get every ounce of affordable quality I can out of my factory system is all 

Thanks for the helps by the way everyone, you guys rock!


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## USS Enterprise (May 26, 2007)

Theguy6792 said:


> Just as FordEscape said, I am looking to utilize every signal coming from my factory amp. I originally had the front signal for my LC2i, which in that case everything worked fine as I have stock rear speakers. However once I upgrade the speakers and amplify them on my Alpine, the factory rear signal would be nonexistent. I would have lost other (minor) features. Such as when the Nav voice kicks in, the music fades to the rear at a lower volume. If I had no rear signal after upgrading my speakers the audio would just cut out completely.
> 
> Also another factor was that I found a LC7i at a STUPIDLY cheap price (lower than I paid for my LC2i), and was able to sell my LC2i for almost $35 more than I paid for it (out of country buyer). So I basically went for it. I lost nothing but gained a few bucks and a better unit.
> 
> ...


Got you guys. Sorry, I was hoping it would be that simple. But hell, making a few bucks on the deal isn't bad at all.
Either way, I hope you get it figured out.


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## FordEscape (Nov 23, 2014)

USS Enterprise said:


> ..... But hell, making a few bucks on the deal isn't bad at all.
> Either way, I hope you get it figured out.


Ditto on all that :thumbsup:



Theguy6792 said:


> ....I am just trying to get every ounce of affordable quality I can out of my factory system is all  ...


Please do post a follow-up here and let us know how it goes


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## credible (Sep 1, 2014)

USS Enterprise said:


> Got you guys. Sorry, I was hoping it would be that simple. But hell, making a few bucks on the deal isn't bad at all.
> Either way, I hope you get it figured out.


I just saw one up here in Ontario, think I will grab one as well, same boat as the OP, I have an LC2i but on the Mustang Shaker 500 the bluetooth and sounds only come out of the fronts speakers so I can get away with the value option.

But I really want to send the 8 inch front door signal to the sub and with the LC2i I can't do that.


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## Theguy6792 (Jun 8, 2017)

FordEscape said:


> USS Enterprise said:
> 
> 
> > ..... But hell, making a few bucks on the deal isn't bad at all.
> ...


Just following up like you asked. Set some time aside this morning to rewire my whole car basically, lol. Ran all new speaker output lines from the OEM amp, as well as new speaker lines to the Alpine amp. Walked in my house to take a break and my LC7i was sitting in my door 

Immediately ran out to hook it up and DAMN, well worth the upgrade!

Installed as followed:
Tweeters - CH1
Front Mids - CH2
Rears - CH3

I then summed CH1 & CH2, and left CH3 separate. AutoSum is off. Now I am waiting for my RCA splitters to be delivered today so that I can have my rears functioning again.

One thing I really like is that since I have my tweeters running to CH1, the adjustment knob controls the output on the highs only (since they are crossed over from the OEM system I guess). I can crank it to have some ear piercing highs or tone it down if things get too sharp.

The middle knob is for my mids and of course the Accubass knobs.

All in all it was a worthy upgrade. I attached a few photos of everything. Don't mind the mess in the first photo I was just testing everything out. The finished product is posted as well. At least until I build the motivation to make an amp rack/beauty board.

BTW I went bonkers with the Tessa tape for a clean look. I frigging love that stuff!


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## Theguy6792 (Jun 8, 2017)

Also, forgot to mention. I was able to retain 100% of my factory functions. Fade/Balance as well as the audible menu noises and Nav voice!


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## Sk33zoids (Jun 22, 2017)

Hi all..So i need some help in just making sure that i am going in the right direction..So i have 4 morel 6xx8 mids and a 4 channel zapco amp with an lc7i..Im jus wanting to intergrate the lc7i into my wiring scheme..Now I have to passive crossover that came with the morel components installed so i have the front running though theit respective crossovers and i have the rear doing the same..I also have tweets just for the front running through that same pasive crossover..so my questions are I take the wires from each crossover that u would normally run to the amp and run it into the lc7i instead ? so with the tweeters in the front do i want to sum the main channel(Fronts) beings that i have the highs(tweets) also connected to their crossover one in the left door and the right door..and jus run those to the lc7i and then take the rears without tweets and run them to the 2nd ouput channel of the lc7i..then just connect the rcas from lc7i to aftermarket amp..correct..I hope i didnt confuse u..my question really is should i sum the main channelbecause of the tweets running through also..and on the aftermarket amp i dont have to use the speaker level inputs for anything if im already using the rca inputs..for some reason i keep thinking i need to connect the LOC and AMP via rcas and then i need to run a speaker wire from eack speaker to the amp at the speaker level inputs also..but thats not right is it..jus one connection is needed the rcas..


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