Bubbacon

I have as well (not poly fill, but foam) and the sound is still no where near what the fronts put out.

JeeP_MarK

I got a feeling there might be a some kind of cap put on the rear speakers from the amp not the head unit , maybe if you are not doing any thing with the old amp .Try opening it up to see if there is a hidden gain control or trace the wires from amp to the rear speakers to see If there is a hidden capacitor , it might even be hidden in the speaker bar out of site, hope you find a answer to this mystery

JeeP_MarK

Question for anyone ? How many wires going into and out of the amp ? I was thinking these pricks are using a 4 channel amp and not a 5 channel, running the sub wire off the rear channel and it has a crossover connected to both the rear speaker and the sub, this is why they sound like crap, I bet if some one hooked there rear speaker directly out of the amp and added a small amp to the factory sub this stock system would sound 100 % better ,You could upgrade the stock sound for under $100. Dam I wish I had my jeep near me it would be super easy to trace the sub wire back to see if there connected,

Bubbacon

Thanks - I'm a sound engineer wanna' be... really hard (for me anyway) to trace/understand input from output to the sound bar. What I will try is to trace both the sub and the sound bar wires from the speakers back in order to see what it looks like. If they home run back to the amp I am stuck.

In my demented logic... I would "assume" that the amp is doing the job an amp should... and that is amplifying and 'tuning' the incoming signal from the HU, and pushing it to the speakers. Therefore, my basic conclusion is that the HU is not pushing enough signal out to the rear channels.

What I would LOVE TO KNOW, is has anyone replaced a stock HU for an aftermarket in an Infinity setup (running through the stock amp) by utilizing simple wiring harness adapter from likes of Crutchfield. If so, did the single replacement of the HU improve the sound bar? If so, theres our answer.

JeeP_MarK

From what I have read the stock head unit and amp use canbus to turn on ,if you use a after market head unit there will be no communication to turn on the amp from the head unit , I am no wear near my jeep do to me being out of town I would investigate more on my theory. My is the mygig rer head unit and is used other jeep product with no problems to the rear speaker, and came form a Ram truck so there should be no issues to the rear but there is ,while I was sitting in my machine to day doing nothing decided to do some research and could not find anything on sub amps for any jeep product except the kicker set up in the grand Cherokee so do me a favor and look at the old amp you pulled and tell me how many connections are on the speaker output of the amp? also I noticed on another thread there was a pic of the infinity amp and there looked like a black panel on one side that looks like it comes off. Please let me know what's behind it ? This has peeked my curiosity . if there was a hidden gain control it might be located behind this panel like this . One last thing I would try running new wire from the amp to your speaker bar to test if you get better sound before changing your head unit. Hope this helps

JeeP_MarK

Hard to search on a iphone so when I got back to my hotel room i found some more info. Its the amp not the wiring. https://www.jk-forum.com/forums/show...oundbar-volume! sorry for bad info and I was was also wrong about the pannel but if you still want to open it up to see if there is a gain inside that would be kool

Bubbacon

Thanks. However - I have replaced the amp with the Kicker upgrade and the improvement is very real. BUT... the sound bar is still not at the levels that the fronts are. THe front speakers sound incredible, but the soundbar, while improved, still are not what they should be (Yes, all speakers have been replaced with Polk/Alpine... including the sub, and I have stuffed the soundbar with poly fill)

So, what I'm trying to learn is where the limit to the soundbar is originating from... I now suspect it's from the HU and channel.

THe question is pretty simple... who has replaced the stock HU and kept the JK amp (using a harness adapter) ... what did this do to the soundbar?

ZombJep

Pretty sure the factory amp is only powering the front speakers and sub. I upgraded the speakers in the soundbar and they still sound weak. My guess would be you have to either add another amp for the soundbar or upgrade to a 5 channel amp. I am going to try to go to a stereo shop tomorrow and see what they say. If I get some useful info. I will post up tomorrow.

strider_mt2k

Installed a pair of Polk db651s and did a little fiddling with the audio controls.

CreepyJeeper

its the factory head unit. my JKU does not have a factory amp and with the factory HU and speakers the sound to the rear sound bar is extremely regulated. i replaced mine with a pioneer and the stock speakers sound A LOT better front and rear.. almost seems like they sound better than the aftermarket infinity kappas that i bought with pioneer... anyway, i used polyfill as well in the front and rear and got a much more rich and clear tone. it didn't seem so hollow. still not as good as the kappas would sound with an aftermarket amp, but that is just not high on my priority list right now... lol. hope this helps.