Upgrading, but still have JBL premium amp, why’s it still sound like sh—?

Hi all, I was one to take advantage of the Alpine Halo super sale at Best Buy, so I began the upgrade by getting that long with the Maestro RR and replacing the JBL premium HU. That alone gave the speakers a bit more and sounded much better.

I next upgraded to what are now Alpine R series in front (6x9 and tweeter components) and back (6.5 and tweeter components). Sounded much better again, but I know I can get more out of them with a better amp.

So, there’s a factory amp powering all truck speakers, if I’m not mistaken. 3 dash speakers, 4 door speakers and their 4 tweeters, and the sub.

Once I added the new 4-channel Kicker 360W amp for the doors, it all sounded like crap. 8” sub seems to produce no bass (although it’s debatable it produced much before). I feel like I’ve read somewhere that the factory amp diverts signals in a funny way that only makes sense when it’s all stock (or when you don’t add a multichannel amp). I just can’t find the information.

Next week I’ll be adding a Kicker CompRT 12” in slim box with a passive radiator, and Kicker 800W Class D mono amp. I’ll pull the 8, and I’ll pull the factory amp. Should this solve my issues and restore my sound? I know the 12 should thump, but will removing the factory amp make this system workable? Was just weird to me that I upgraded so many pieces and all of a sudden, the base was so diminished that my AirPods hit harder.

I’ve also heard that once there are upgrades done, some folks aren’t using the 3 dash speakers. I’ve heard they crowd out the other speakers, and move the sound forward in a way that’s undesirable. Can anybody maybe confirm this or tell me another solution? Will they even have power if I’ve removed that amp?

I’m clearly a newb to audio, so mansplain away.

 

What year is your truck?

I didn't have the JBL on mine, but yeah....to keep the JBL head unit/amp, it was recommended running something like the

$315 Rockford Fosgate DSR1 8-Channel Interactive Signal Processor w/Integrated iDatalink Maestro Module

Rockford Fosgate DSR1, but ultimately its best to just pull everything.

I would disconnect the factory dash speakers.....unless you are going to run an 8ch amp.

 

Oh my bad, I forget to update each burner I do. It’s a 2017 Platinum with JBL premium. And yeah it sounds like the dash speakers won’t add anything of value, so I think the mono and the 4-channel amp should be enough for the remaining speakers.

 

For these components, did you use the Alpine supplied crossover network and if so, I assume that you used the factory wiring from the woofers as your input to the crossover and then connected the Alpine woofer and tweeter to the respective crossover outputs? or just simply swapped out the factory JBL with the Alpines, direct to the factory wiring? Just trying to see this through. Because if you did use the woofer wiring as the input to the Alpine crossover, I would dare say you're not getting the full sound spectrum. Perhaps just the lower end that was crossed over in the JBL OEM amplifier - specific to that JBL driver.

What did you use to feed the Kicker amp input? RCA cables directly from your Alpine HU? or high level speaker outputs from the OEM JBL Amp? Again, if using the output from the JBL amp, I dare say you are not getting the full sound spectrum.

Best thing you can do is bypass the factory amp. Run RCA cables from the HU for the Front, Rear & Sub outputs to the respective Kicker amp(s).

For the record, I do not have the JBL system. But did do an overhaul with my non-JBL system. Including the use of the dash speakers in a 3-way application. Disconnected the center channel though.