How To Hook Up Amp to Stock Radio (2023 OR)

I had a shop install a RCA jack splice at the OEM radio head unit and ran that to my amp (RCA jack input). The amp is a JP 234 and my understanding is that this amp uses "low level" inputs. I think the OEM head unit is "high level" outputs. I am getting a lot of distortion and clipping out of the amp even at low volume. I am thinking the shop tapped high level outputs and should have used a line output converter. The shop only charged $20 so I am thinking the splice box has no electronics and is just a junction box.
Any advice appreciated.
Thanks

 

You’ll probably want to pull the head unit out and check. $20 doesn’t even buy you a decent LOC, much less pay for labor

 

I pulled the head and there is a small back box spliced into the wires existing the head unit. My son had the audio shop do this. Son said he paid $20 to do the work. Agree that probably only a splice and no electronics. I am going to call the shop in a few minutes when it opens and asked what was installed. Question is does the OEM head unit put out high or low outputs? Is the only output on the head unit what is going to the factory speakers (in which case I would assume the outputs are high)?
thanks

 

From what you wrote, you had a shop install RCAs spliced into your speaker wires. Did you specifically ask them to do this or did you ask them to correctly run wires with a LOC for the amp? Sounds like you got what you asked them to do. Get a LOC and run the wires from the HU to the LOC, then the LOC to the amp. It's not hard.

 

My son had the shop do the work. He did not really know what they installed (young kid). I am just trying to help him get the thing right. I probably would have ordered all as a package from say crutch, but he is learning from his mistakes. What we have is a cable with the four channel RCA's running from the head to the amp. The amp is using the two front speaker taps and then split into four to run to the 4 channel amp. We built a speaker box that has tweeters and mid range speakers (running parallel to get the 2 ohm load the amp wants to see. So this set up does work, just does not sound that great. Problem may be over driving the amp. So what type of LOC should we use with the head unit? Is the LOC designed to run off the stock head unit speaker outputs as apparently are now tapped into?
Thanks

 

Yes. Line output converters are specifically made to take high-level inputs from your OEM radio and convert them into low-level outputs for the amp. You will need to re-wire everything. Run speaker wire from the HU to the LOC, then run RCA from the LOC to the amp. Get the LC6i and you can add a 5th channel for a sub later on if needed.

https://www.crutchfield.com/S-fiQgyxIq2lv/p_161LC6IB/AudioControl-LC6i-Black.html

There are plenty of youtube videos on how to install radios. I would also suggest posting in the regional forums to see if anyone is available to help show how the wiring can be run. I'm in the middle of VA, so I doubt I could help, but maybe you'd find someone local. Just offer some pizza and soda. It shouldn't take more than a couple hours.

 

I just called the shop and they tell me the tap they installed at the head unit is a high to low line converter. They suggested some settings to try on the JP234 amp but basically we tried every setting and still do not get great results. The shop said we could come by and they would take a look at it They way it is now the LOC is installed at the head (shop says it is a high to low) and the converter has the RCA's, we then run to the amp installed behind the rear seat and then two the speaker box located above the head rest. I may have son run by the shop that installed the LOC and see what they say. Also, I want to pull the head again and find the make of the LOC. I have heard I need a full range LOC, maybe the one installed is a cheap unit. I will check the one on this thread from previous poster.
Thanks

 

I doubt it is a quality LOC. For $20, it sounds like a cheap voltage reducer bought from ebay. I wouldn't go back to that shop for anything.

 

https://www.crutchfield.com/S-fiQgyxIq2lv/p_161LC6IB/AudioControl-LC6i-Black.html
That unit looks a heck of a lot better than the 1 inch cube installed now. Maybe that is the problem, cheap LOC currently installed.
Thanks

 

Agree, think we will buy new LOC and see how that goes.
Thanks

 

I probably will buy a newer higher quality LOC. Question on how to wire. With the current low quality LOC, the factory speakers are still connected up and if I turn the amp off, the factory head unit and speakers operate as OEM. With amp on, the new speakers and the factory speakers operate together. So how is the LOC wired in? Is it ok to just leave the factory speakers and tap the + and - and basically have the new LOC wired parallel to the existing speakers? Seems that is the way current system is wired. Is that ok or could this cause issues?
Thanks

 

Another question, can I leave the RCA cable in place that is now running from the head unit to the area behind the back seat, using the necessary connectors / wire to run the high level head unit output to the new LOC located behind the back seat, or do I need to pull speaker wire? Can the RCA cable handle the head unit output? Make life easier to use this RCA cable we already installed.
Thanks

 

can you post a picture of the items you've got?
is this the amp?
https://www.down4soundshop.com/down4sound-jp234-black-2000w-rms-4ch-amplifier/

 

You can leave the rca wire . Just get a good Loc like an lc6i and your good to go. That would be a good one if you want to add a sub down the road which I highly suggest. Changing the OEM speakers will be a game changer also .If you didn’t already . Then next step add a nice powered sub and your at next level

 

Yea, that is the amp. Tried to get son to pull the head unit yesterday to look at the LOC that was installed. He was a little worn out from working night shift so did not do it. I will call shop today and ask what they installed. Son did buy a sub woofer amp and speaker (need to build the box) that will be installed once we get the jp 234 amp working well.

 

It looks like we need to mount the lc6i behind the rear seat due to space. So from the head unit to the lc6i can I use the RCA cable we now have installed (LOC was connected by shop at the head unit), or due to high power do I need to run speaker wire from head unit to the lc6i?
Thanks

 

The inputs on the LC6i are speaker wires. Only the outputs are RCA, so you will need speaker wires run from the HU.

 

I was thinking cut the rca plug off and connect the wire to the head output, but maybe the rca wire is too small and would introduce losses.

 

https://www.bestbuy.com/site/reviews/axxess-2-channel-line-output-converter-black/9616444?variant=A&rating=4,3
Spoke with shop. The LOC they installed is something like in the above link and Axxess 2 channel. Shop says have son stop in and they will take a look. Shop says the LOC does have some adjustments. Son is working and will stop by the shop after work and have them take a look, figure give them a chance to maybe solve the problem. If not, go to better LOC. If you look at reviews in above link- not too bad...
I'll let you know the outcome.
Thanks

 

You can only get so much out of a cheap converter.

I have had great success with LC branded converters. LC2i is reliable.

Good luck with having the shop make adjustments, hope it works out.

https://www.crutchfield.com/S-PCiph...uQjvmBcnFnFgBaSF58SPs7pGgbYiDVjYaAqHGEALw_wcB